Resolved Young Binary Systems and Their Disks

We selected targets from a single star-forming region, Taurus (distance ∼140 pc), so that effects such as age and cluster environment were kept constant as much as possible. Taurus is ideal in having a significant population of young stellar objects that have evolved into the disk-only state (with no remaining envelope) and in being very well studied, containing both a well-known set of single stars with disks and a significant population of binaries where both stellar components have been characterized in the optical or near-infrared. We started with the list of Taurus objects from Luhman et al. (2010) and selected those with Class II spectral energy distributions (SEDs), which resulted in 211 stars in 166 systems. Twelve of these stars are spectroscopic binaries. Some of the multiple star systems were classified using separate SEDs, but most of the binary star systems are unresolved in the mid-infrared and were classified as a pair. We then eliminated all single and close (<018 or 25 au) multiple sources that had been previously detected at millimeter wavelengths, as well as multiple systems where all resolvable (i.e., separations >018) components have been detected (Harris et al. 2012; Andrews et al. 2013; Paper I). We also removed sources with scheduled observations in ALMA Cycle 1. The remaining list included 69 single and multiple systems with 94 resolvable disks, including one G star, seven K stars, and the rest M stars.

To construct the observing groups for ALMA, the sample was divided into close multiple systems (separations <1''), and singles and wide multiples, to allow for different spatial resolution observations. Within these groups, the sample was split to follow the ALMA guidelines on maximum angular separation from the gain calibrator. These divisions resulted in five source groupings; four of these were observed in Cycle 2, and one of the four was re-observed in Cycle 3. Table 1 lists the basic information for these observation sets. One source group was never observed. The data obtained included observations of 45 systems, with a total of 65 stars.

We selected Band 6 (1.3 mm) for these ALMA observations. Three of the correlator sections were set for continuum emission sensitivity, with the fourth set to the transition for CO(2–1) at 230.5 GHz. The total continuum bandwidth was 7.5 GHz. For the data sets from 2015, we used the calibration provided by ALMA and created images using the CASA package (McMullin et al. 2007). For sources with sufficient continuum flux, we also performed self-calibration. The data taken in 2016 July did not pass the internal quality assessment at ALMA, so we processed the raw data using the pipeline scripts in CASA. Based on the gain calibration and measured fluxes for sources with previous measurements, we deemed the data usable and they are included in the analysis below.

For each target, the CASA routine clean was used to produce an image. As the source positions are known a priori, detections were defined as a >3σ peak at the known location. The flux uncertainty was measured as the rms in the cleaned portion of the image without known sources. The peak flux was measured as the highest flux within the detection, while the integrated flux was measured using the routine imfit and fitting a two-dimensional Gaussian.

Table 2 lists all sources observed at ALMA with the detected Band 6 (1.3 mm; 230 GHz) peak flux and observed rms or 3σ limit. For all detected sources, the integrated flux, the beam size and orientation, and the center of the emission are listed. An integrated flux is not listed if the source was reported as unresolved by imfit. The results from imfit are also used for the reported positions of the detections and to derive the measured component separations given in Table 3. These observations resulted in 21 new detections: six single stars, four primary stars, and 11 companion stars.

Figure 1 plots the continuum emission for the multiple systems where the emission is unresolved or well fit by a Gaussian. In every multiple system observed, we detected continuum emission from at least one disk. The positions of the components are marked in the case of non-detections. In some cases, older catalog coordinates were used to set the ALMA pointing, resulting in the offsets seen in Figure 1. We have confirmed that our detected positions correspond to the expected stellar positions, and the differences due to orbital motion are discussed below. Figure 2 plots the continuum emission from all detected single stars.

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For three of the sources, our high angular resolution observations trace structure in the disk. Figure 3 shows the well-studied circumbinary ring of GG Tau. Note that we can localize the central emission to arise from a circumstellar disk around GG Tau Aa. UX Tau A was identified as a pre-transition disk by Espaillat et al. (2007) using Spitzer data, and our ALMA data show a strong clearing in the inner disk (Figure 4). From the mid-infrared spectra, CIDA 9 was not identified as a transition disk by Furlan et al. (2011), but the ALMA data show a ring-like structure with an emission deficit in the center (Figure 5).

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For 11 of the binary or multiple star systems, we detected emission from two components in the system and thus were able to measure projected separations and position angles, shown in Table 3. Although our positions measure the centroid of the millimeter-wavelength emission rather than the stellar position, comparison of our measured positions with those from Gaia DR2 (Gaia Collaboration et al. 2018) typically agree to within a few tens of milliarcseconds, comparable to the ALMA astrometric uncertainty for our data, indicating that our measured positions trace the stellar positions very well and that the millimeter emission is not substantially asymmetric or offset from the stars at our resolution. As such, we can compare our measured separations and position angles with those in the literature from earlier epochs. The four widest sources, HN Tau AB, JH 223 AB, Haro 6–28 AB, and Haro 6–37 AC, all have position angles and projected separations that agree with previous observations (Table 3). In contrast, all of the sources with projected separations of 05 or less (∼70 au at an assumed distance of 140 pc) show detectable orbital motion. In some cases the motion is substantial (e.g., a 60° change in position angle for FO Tau), but in all of these cases it is within the amount of motion expected from simple assumptions about the orbits (e.g., modest eccentricities and that the semimajor axis is similar to the current projected separation). Many of these systems had tentative initial detections of orbital motion in Woitas et al. (2001) and our results show continued motion consistent with their results. Perhaps the most surprising system is Haro 6–28 AB which, with a projected separation of 065, might have been expected to show orbital motion, but which has a separation and position angle consistent with that measured by White & Ghez (2001) in 1997, suggesting that it may be near periastron in an eccentric orbit and/or that the true separation may be substantially larger than the projected separation. We also note that, given the few tens of mas yr⁻¹ proper motions of typical sources in Taurus, comparison with previous measurements shows that all of the sources in Table 3 are common-proper-motion systems.

To determine disk masses, we need to know the distance to each of our sources. Gaia DR2 (Gaia Collaboration et al. 2018) contains parallax measurements for most of our sources, but since many of our sources are binaries, we need to be careful that the astrometric solution is not affected by orbital acceleration in the system. To assess the quality of each astrometric solution, we followed the procedure recommended in Gaia Technical Note GAIA-C3-TN-LU-LL-124-01 (Lindegren 2018). For each star with a measured Gaia parallax, we calculated the renormalized unit weight error (RUWE) of the astrometric solution, retaining only those with RUWE ≤ 1.6. For sources with good astrometric solutions, we took distances and uncertainties from Bailer-Jones et al. (2018). In all cases, we used the distance of the brightest Gaia source within 8'' of the 2MASS position; in particular, this means that we used the same distance for all components in a given binary or multiple system. The lone exception is the pair GI and GK Tau, which are separated by 132. For sources without reliable Gaia DR2 distances, we used the weighted mean of the Gaia distances for all other sources in our sample within 30'. A small number of our sources had no neighbors within 30' in our sample with reliable Gaia distances; in those cases, we adopted the median distance from our sample of 138.8 ± 18.8 pc.

Assuming the dust is optically thin, the conversion from flux (F_ν) to disk mass (M_d) is

$$\begin{eqnarray}&&{M}_{d}=\displaystyle \frac{{F}_{\nu }{d}^{2}}{{\kappa }_{\nu }{X}_{g}{B}_{\nu }({T}_{d})}.\end{eqnarray} \tag{ 1 }$$

For comparison to the Taurus sample results of Andrews et al. (2013), we use the same constants of dust-to-gas ratio X_g = 0.01 and dust opacity κ_ν = 2.3 cm² g⁻¹ at 1.3 mm. For our new ALMA sources, the uncertainty listed in Table 4 includes both the observed uncertainty from Table 2 and a 5% absolute flux calibration uncertainty (ALMA memo 594). For the mean dust temperature T_d, we also adopt the Andrews et al. (2013) scaling of ${T}_{d}=25{({L}_{* }/{L}_{\odot })}^{-1/4}$ K. Our derivation of the stellar luminosity is described in Section 3.3 and the calculated dust temperatures range from 7 to 67 K, but the dust temperature for 95% of the single and binary star sample defined in Section 4.1 ranges from 10 to 30 K. The derived disk mass or limit is given in Table 4 and shown for all stars in Figure 6.

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Table 4.  Taurus Sample Disk and Stellar Properties

2MASS Designation	Source Name	Rolea	Samp.	Binary	Flux	Referencesb	Sp. Type	Referencesb	log M*	log L*	log Mdisk	Distance
				sep. ('')b	(mJy)				(M⊙)	(L⊙)	(M⊙)	(pc)c
J04135737+2918193	IRAS 04108+2910	−9	N	...	<19.80	8	M3	12	$-{0.54}_{-0.19}^{+0.10}$	$-{0.50}_{-0.19}^{+0.12}$	<−2.73	123.07 ± 1.53
J04141188+2811535	J04141188+2811535	0	N	...	0.28 ± 0.08	11	M6.25	13	$-{1.25}_{-0.20}^{+0.27}$	$-{1.57}_{-0.32}^{+0.43}$	−4.25 ± 0.16	130.70 ± 2.86
J04141358+2812492	FM Tau	0	Y	...	13.10 ± 2.70	8	M4.5	14	$-{0.83}_{-0.23}^{+0.20}$	$-{0.85}_{-0.39}^{+0.26}$	−2.76 ± 0.13	131.44 ± 0.81
J04141458+2827580	FN Tau	0	Y	...	16.80 ± 2.10	8	M3.5	14	$-{0.62}_{-0.20}^{+0.14}$	$-{0.59}_{-0.26}^{+0.16}$	−2.72 ± 0.10	130.76 ± 1.06
J04141700+2810578	CW Tau	0	Y	...	52.30 ± 7.00	8	K3.0	14	${0.05}_{-0.08}^{+0.07}$	${0.38}_{-0.14}^{+0.11}$	−2.46 ± 0.10	131.94 ± 0.68
J04141760+2806096	CIDA 1	0	Y	...	13.50 ± 2.80	8	M4.5	14	$-{0.83}_{-0.23}^{+0.20}$	$-{0.85}_{-0.39}^{+0.26}$	−2.72 ± 0.13	135.19 ± 1.59
J04142626+2806032	MHO 1	1	N	...	216.00 ± 0.76	9	M2.5	15	$-{0.48}_{-0.14}^{+0.08}$	$-{0.43}_{-0.16}^{+0.11}$	−1.64 ± 0.09	132.32 ± 3.85
J04142626+2806032	MHO 2 AB	−2	N	...	133.30 ± 0.79	9	M2.5/5.2	15	$-{0.18}_{-0.14}^{+0.08}$	$-{0.35}_{-0.20}^{+0.17}$	−1.87 ± 0.09	132.32 ± 3.851
J04143054+2805147	BHS98 MHO 3 AB	−1	N	...	<12.00	8	K7/M2	15/8	${0.11}_{-0.01}^{+0.04}$	${0.14}_{-0.04}^{+0.09}$	<−2.52	241.36 ± 11.29
J04144730+2646264	FP Tau	0	Y	...	6.04 ± 0.20	11	M2.6	14	$-{0.49}_{-0.16}^{+0.08}$	$-{0.44}_{-0.17}^{+0.11}$	−3.22 ± 0.09	128.01 ± 0.85
J04144786+2648110	CX Tau	0	Y	...	9.40 ± 2.30	8	M2.5	14	$-{0.48}_{-0.14}^{+0.08}$	$-{0.43}_{-0.16}^{+0.11}$	−3.04 ± 0.12	127.46 ± 0.65
J04144928+2812305	FO Tau A	1	Y	0.1501	3.07 ± 0.19	7	M3.5	16	$-{0.62}_{-0.20}^{+0.14}$	$-{0.59}_{-0.26}^{+0.16}$	−3.45 ± 0.09	132.07 ± 1.502
J04144928+2812305	FO Tau B	2	Y	0.1501	2.94 ± 0.19	7	M3.5	16	$-{0.62}_{-0.20}^{+0.14}$	$-{0.59}_{-0.26}^{+0.16}$	−3.47 ± 0.09	132.07 ± 1.502
J04153916+2818586	J04153916+2818586	−9	N	...	13.40 ± 1.40	8	M4.0	14	$-{0.73}_{-0.19}^{+0.19}$	$-{0.68}_{-0.35}^{+0.19}$	−2.80 ± 0.10	131.01 ± 1.40
J04154278+2909597	IRAS 04125+2902	−9	N	...	19.90 ± 2.50	8	M1.25	12	$-{0.37}_{-0.09}^{+0.10}$	$-{0.28}_{-0.12}^{+0.15}$	−2.55 ± 0.10	159.24 ± 1.69
J04155799+2746175	J04155799+2746175	−9	N	...	12.60 ± 1.40	8	M5.2	14	$-{0.97}_{-0.27}^{+0.20}$	$-{1.12}_{-0.43}^{+0.39}$	−2.69 ± 0.13	135.19 ± 1.97
J04161210+2756385	J04161210+2756385	0	Y	...	2.19 ± 0.12	11	M4.75	13	$-{0.87}_{-0.38}^{+0.19}$	$-{0.94}_{-0.65}^{+0.29}$	−3.48 ± 0.11	137.00 ± 2.21
J04163911+2858491	J04163911+2858491	0	Y	...	<2.50	8	M5.5	17	$-{1.05}_{-0.27}^{+0.23}$	$-{1.25}_{-0.45}^{+0.39}$	<−3.22	159.24 ± 1.692
J04173372+2820468	CY Tau	0	Y	...	79.40 ± 5.90	8	M2.3	14	$-{0.46}_{-0.12}^{+0.09}$	$-{0.41}_{-0.14}^{+0.12}$	−2.11 ± 0.09	128.41 ± 0.73
J04174955+2813318	KPNO 10	0	Y	...	7.80 ± 1.40	8	M5	18	$-{0.92}_{-0.29}^{+0.19}$	$-{1.03}_{-0.49}^{+0.35}$	−2.91 ± 0.13	136.89 ± 2.20
J04174965+2829362	SS94 V410 X-ray 1	0	Y	...	<3.40	8	M3.7	14	$-{0.67}_{-0.20}^{+0.17}$	$-{0.63}_{-0.29}^{+0.18}$	<−3.42	128.57 ± 1.27
J04181078+2519574	V409 Tau	−9	N	...	18.70 ± 1.40	8	M0.6	14	$-{0.30}_{-0.10}^{+0.08}$	$-{0.18}_{-0.15}^{+0.11}$	−2.78 ± 0.09	130.87 ± 0.69
J04181710+2828419	V410 Anon 13	0	Y	...	0.47 ± 0.08	11	M5.75	19	$-{1.25}_{-0.13}^{+0.38}$	$-{1.58}_{-0.20}^{+0.65}$	−4.07 ± 0.19	124.31 ± 5.21
J04183112+2816290	DD Tau A	1	Y	0.5701	9.20 ± 4.30	8	M3.5	16	$-{0.62}_{-0.20}^{+0.14}$	$-{0.59}_{-0.26}^{+0.16}$	−3.00 ± 0.18	128.39 ± 0.962
J04183112+2816290	DD Tau B	2	Y	0.5701	3.40 ± 1.90	8	M3.5	16	$-{0.62}_{-0.20}^{+0.14}$	$-{0.59}_{-0.26}^{+0.16}$	−3.43 ± 0.21	128.39 ± 0.962
J04183158+2816585	CZ Tau A	1	Y	0.3171	<0.36	7	M3	20	$-{0.54}_{-0.19}^{+0.10}$	$-{0.50}_{-0.19}^{+0.12}$	<−4.43	128.39 ± 0.962
J04183158+2816585	CZ Tau B	2	Y	0.3171	0.62 ± 0.12	7	M6	8	$-{1.22}_{-0.20}^{+0.29}$	$-{1.52}_{-0.31}^{+0.49}$	−3.94 ± 0.15	128.39 ± 0.962
J04183444+2830302	SS94 V410 X-ray 2	−9	N	...	15.40 ± 2.30	8	M0	12	$-{0.25}_{-0.10}^{+0.04}$	$-{0.11}_{-0.14}^{+0.06}$	−2.89 ± 0.10	128.85 ± 1.142
J04184133+2827250	LR1	−9	N	...	30.80 ± 1.60	8	K4.5	19	$-{0.07}_{-0.04}^{+0.08}$	${0.18}_{-0.07}^{+0.13}$	−2.67 ± 0.09	128.85 ± 1.142
J04184250+2818498	SS94 V410 X-ray 7 AB	−1	N	...	<13.00	8	M0.5/2.75	15/8	${0.01}_{-0.10}^{+0.07}$	${0.01}_{-0.16}^{+0.10}$	<−3.02	125.27 ± 4.07
J04190110+2819420	V410 X-ray 6	0	Y	...	<0.16	11	M5.9	14	$-{1.24}_{-0.16}^{+0.33}$	$-{1.56}_{-0.25}^{+0.57}$	<−4.59	119.03 ± 2.19
J04190126+2802487	KPNO 12	0	N	...	<2.10	8	M9.25	22	$-{1.77}_{-0.13}^{+0.14}$	$-{2.35}_{-0.15}^{+0.21}$	<−3.20	128.36 ± 1.092
J04191281+2829330	FQ Tau A	1	Y	0.7801	3.10 ± 0.21	9	M3	16	$-{0.54}_{-0.19}^{+0.10}$	$-{0.50}_{-0.19}^{+0.12}$	−3.49 ± 0.09	128.85 ± 1.142
J04191281+2829330	FQ Tau B	2	Y	0.7801	2.70 ± 0.15	9	M3.5	16	$-{0.62}_{-0.20}^{+0.14}$	$-{0.59}_{-0.26}^{+0.16}$	−3.53 ± 0.09	128.85 ± 1.142
J04191583+2906269	BP Tau	0	Y	...	41.50 ± 2.20	8	M0.5	14	$-{0.29}_{-0.10}^{+0.07}$	$-{0.17}_{-0.15}^{+0.10}$	−2.45 ± 0.09	128.61 ± 0.96
J04192625+2826142	V819 Tau	0	Y	...	0.53 ± 0.14	10	K8	14	$-{0.20}_{-0.01}^{+0.01}$	$-{0.03}_{-0.01}^{+0.01}$	−4.36 ± 0.12	131.22 ± 1.10
J04193545+2827218	FR Tau	−9	N	...	<15.00	8	M5.3	14	$-{1.00}_{-0.27}^{+0.21}$	$-{1.17}_{-0.42}^{+0.41}$	<−2.64	128.39 ± 0.962
J04201611+2821325	J04201611+2821325	−9	N	...	<1.70	8	M6.5	12	$-{1.33}_{-0.17}^{+0.27}$	$-{1.70}_{-0.25}^{+0.45}$	<−3.46	128.66 ± 3.35
J04202144+2813491	J04202144+2813491	−9	N	...	52.40 ± 1.50	8	M1	12	$-{0.35}_{-0.09}^{+0.10}$	$-{0.25}_{-0.13}^{+0.14}$	−2.35 ± 0.09	126.23 ± 1.592
J04202555+2700355	J04202555+2700355	0	Y	...	5.79 ± 0.16	11	M5.25	13	$-{0.98}_{-0.27}^{+0.21}$	$-{1.14}_{-0.43}^{+0.40}$	−2.82 ± 0.13	169.80 ± 5.38
J04202583+2819237	IRAS 04173+2812	−9	N	...	<2.00	8	M4	12	$-{0.73}_{-0.19}^{+0.19}$	$-{0.68}_{-0.35}^{+0.19}$	<−3.68	122.27 ± 6.43
J04202606+2804089	J04202606+2804089	−9	N	...	<4.30	8	M3.5	14	$-{0.62}_{-0.20}^{+0.14}$	$-{0.59}_{-0.26}^{+0.16}$	<−3.34	127.05 ± 0.86
J04210795+2702204	CFHT-BD-Tau 19	0	Y	...	<2.70	8	M5.25	12	$-{0.98}_{-0.27}^{+0.21}$	$-{1.14}_{-0.43}^{+0.40}$	<−3.20	160.31 ± 2.412
J04210934+2750368	J04210934+2750368	−9	N	...	<1.80	8	M4	23	$-{0.73}_{-0.19}^{+0.19}$	$-{0.68}_{-0.35}^{+0.19}$	<−3.76	117.94 ± 1.37
J04213459+2701388	J04213459+2701388	0	Y	...	<0.17	11	M5.5	13	$-{1.05}_{-0.27}^{+0.23}$	$-{1.25}_{-0.45}^{+0.39}$	<−4.35	166.34 ± 3.85
J04214323+1934133	IRAS 04187+1927	0	Y	...	3.70 ± 0.21	7	M2.4	14	$-{0.47}_{-0.13}^{+0.08}$	$-{0.42}_{-0.15}^{+0.11}$	−3.31 ± 0.09	148.16 ± 2.19
J04214631+2659296	J04214631+2659296	0	Y	...	<3.90	8	M5.75	17	$-{1.25}_{-0.13}^{+0.38}$	$-{1.58}_{-0.20}^{+0.65}$	<−2.93	160.29 ± 7.35
J04215563+2755060	DE Tau	0	Y	...	31.10 ± 3.10	8	M2.3	14	$-{0.46}_{-0.12}^{+0.09}$	$-{0.41}_{-0.14}^{+0.12}$	−2.53 ± 0.09	126.92 ± 1.07
J04215740+2826355	RY Tau	0	Y	...	192.50 ± 9.10	8	G0	14	${0.54}_{-0.01}^{+0.01}$	${1.72}_{-0.08}^{+0.05}$	−2.23 ± 0.08	132.82 ± 2.572
J04220217+2657304	FS Tau A	1	Y	0.2271	2.27 ± 0.18	7	M0	16	$-{0.25}_{-0.10}^{+0.04}$	$-{0.11}_{-0.14}^{+0.06}$	−3.54 ± 0.09	160.31 ± 2.412
J04220217+2657304	FS Tau B	2	Y	0.2271	<0.52	7	M3.5	16	$-{0.62}_{-0.20}^{+0.14}$	$-{0.59}_{-0.26}^{+0.16}$	<−4.06	160.31 ± 2.412
J04221675+2654570	CFHT-Tau-21	0	Y	...	<4.20	8	M1.5	14	$-{0.40}_{-0.08}^{+0.10}$	$-{0.32}_{-0.11}^{+0.15}$	<−3.23	156.97 ± 3.36
J04224786+2645530	IRAS 04196+2638	−9	N	...	51.00 ± 1.20	8	M1	24	$-{0.35}_{-0.09}^{+0.10}$	$-{0.25}_{-0.13}^{+0.14}$	−2.17 ± 0.09	157.03 ± 2.73
J04230607+2801194	J04230607+2801194	0	Y	...	2.28 ± 0.14	11	M6	12	$-{1.22}_{-0.20}^{+0.29}$	$-{1.52}_{-0.31}^{+0.49}$	−3.34 ± 0.14	133.44 ± 2.45
J04230776+2805573	IRAS 04200+2759	−9	N	...	36.60 ± 1.30	8	M2	12	$-{0.44}_{-0.10}^{+0.09}$	$-{0.38}_{-0.12}^{+0.13}$	−2.39 ± 0.09	138.64 ± 3.34
J04231822+2641156	J04231822+2641156	−9	N	...	<3.90	8	M3.5	24	$-{0.62}_{-0.20}^{+0.14}$	$-{0.59}_{-0.26}^{+0.16}$	<−3.22	152.80 ± 3.882
J04233539+2503026	FU Tau A	1	N	...	<1.70	8	M7.25	25	$-{1.45}_{-0.18}^{+0.20}$	$-{1.89}_{-0.26}^{+0.32}$	<−3.39	131.20 ± 2.60
J04233539+2503026	FU Tau B	2	N	...	<1.70	8	M9.25	25	$-{1.77}_{-0.13}^{+0.14}$	$-{2.35}_{-0.15}^{+0.21}$	<−3.27	131.20 ± 2.601
J04233919+2456141	FT Tau	0	Y	...	62.90 ± 4.30	8	M2.8	14	$-{0.51}_{-0.18}^{+0.09}$	$-{0.47}_{-0.19}^{+0.11}$	−2.20 ± 0.09	127.34 ± 0.85
J04242090+2630511	J04242090+2630511	−9	N	...	<1.40	8	M6.5	24	$-{1.33}_{-0.17}^{+0.27}$	$-{1.70}_{-0.25}^{+0.45}$	<−3.48	137.19 ± 3.48
J04242646+2649503	J04242646+2649503	0	Y	...	<3.00	8	M5.75	17	$-{1.25}_{-0.13}^{+0.38}$	$-{1.58}_{-0.20}^{+0.65}$	<−3.08	154.92 ± 3.15
J04244457+2610141	IRAS 04216+2603	−9	N	...	19.80 ± 2.00	8	M2.8	14	$-{0.51}_{-0.18}^{+0.09}$	$-{0.47}_{-0.19}^{+0.11}$	−2.51 ± 0.09	158.92 ± 2.77
J04245708+2711565	IP Tau	0	Y	...	8.80 ± 1.50	8	M0.6	14	$-{0.30}_{-0.10}^{+0.08}$	$-{0.18}_{-0.15}^{+0.11}$	−3.11 ± 0.10	130.09 ± 0.72
J04262939+2624137	KPNO 3	0	Y	...	2.29 ± 0.09	11	M6	12	$-{1.22}_{-0.20}^{+0.29}$	$-{1.52}_{-0.31}^{+0.49}$	−3.21 ± 0.14	155.51 ± 5.55
J04263055+2443558	J04263055+2443558	0	N	...	<0.30	7	M8.75	17	$-{1.70}_{-0.13}^{+0.15}$	$-{2.26}_{-0.18}^{+0.24}$	<−4.13	119.88 ± 10.05
J04265352+2606543	FV Tau A	1	Y	0.7201	6.17 ± 0.16	9	K5	16	$-{0.10}_{-0.05}^{+0.06}$	${0.13}_{-0.08}^{+0.12}$	−3.26 ± 0.09	143.02 ± 6.312
J04265352+2606543	FV Tau B	2	Y	0.7201	5.93 ± 0.18	9	K6	1	$-{0.15}_{-0.04}^{+0.05}$	${0.05}_{-0.07}^{+0.08}$	−3.26 ± 0.09	143.02 ± 6.312
J04265440+2606510	FV Tau/c A	1	Y	0.7401	0.76 ± 0.17	9	M2.5	12	$-{0.48}_{-0.14}^{+0.08}$	$-{0.43}_{-0.16}^{+0.11}$	−4.05 ± 0.12	139.43 ± 2.65
J04265440+2606510	FV Tau/c B	2	Y	0.7401	0.40 ± 0.12	9	M3.5	16	$-{0.62}_{-0.20}^{+0.14}$	$-{0.59}_{-0.26}^{+0.16}$	−4.29 ± 0.14	139.43 ± 2.651
J04265732+2606284	KPNO 13	0	Y	...	<3.60	8	M5.1	14	$-{0.94}_{-0.28}^{+0.20}$	$-{1.07}_{-0.45}^{+0.37}$	<−3.26	132.92 ± 2.27
J04270280+2542223	DF Tau AB	−1	N	...	3.40 ± 1.70	8	M2/2.5	16	$-{0.14}_{-0.10}^{+0.09}$	$-{0.10}_{-0.14}^{+0.12}$	−3.51 ± 0.19	135.66 ± 3.222
J04270469+2606163	DG Tau	0	Y	...	344.20 ± 17.80	8	K7.0	14	$-{0.19}_{-0.01}^{+0.04}$	$-{0.02}_{-0.01}^{+0.07}$	−1.51 ± 0.09	137.41 ± 4.532
J04284263+2714039	J04284263+2714039 A	1	Y	0.6302	0.67 ± 0.10	11	M5.25	13	$-{0.98}_{-0.27}^{+0.21}$	$-{1.14}_{-0.43}^{+0.40}$	−3.97 ± 0.14	132.37 ± 2.53
J04284263+2714039	J04284263+2714039 B	2	Y	0.6302	<0.29	11	M5.25	13	$-{0.98}_{-0.27}^{+0.21}$	$-{1.14}_{-0.43}^{+0.40}$	<−4.34	132.37 ± 2.531
J04290068+2755033	J04290068+2755033	0	N	...	<1.60	8	M8.25	17	$-{1.63}_{-0.14}^{+0.18}$	$-{2.14}_{-0.21}^{+0.26}$	<−3.26	145.71 ± 7.67
J04290498+2649073	IRAS 04260+2642	−9	N	...	120.00 ± 10.00	8	K5	26	$-{0.10}_{-0.05}^{+0.06}$	${0.13}_{-0.08}^{+0.12}$	−2.03 ± 0.09	134.35 ± 0.992
J04292165+2701259	IRAS 04263+2654	0	Y	...	2.89 ± 0.14	11	M5.25	17	$-{0.98}_{-0.27}^{+0.21}$	$-{1.14}_{-0.43}^{+0.40}$	−3.36 ± 0.13	129.11 ± 2.372
J04293606+2435556	XEST 13-010	−9	N	...	15.20 ± 1.20	8	M3	12	$-{0.54}_{-0.19}^{+0.10}$	$-{0.50}_{-0.19}^{+0.12}$	−2.80 ± 0.09	128.97 ± 1.50
J04294155+2632582	DH Tau A	1	N	...	18.00 ± 8.20	8	M1	20	$-{0.35}_{-0.09}^{+0.10}$	$-{0.25}_{-0.13}^{+0.14}$	−2.75 ± 0.18	134.85 ± 1.27
J04294155+2632582	DH Tau B	2	N	...	<3.80	8	M7.5	8	$-{1.50}_{-0.17}^{+0.17}$	$-{1.95}_{-0.25}^{+0.25}$	<−3.00	134.85 ± 1.271
J04295156+2606448	IQ Tau	0	Y	...	61.90 ± 4.50	8	M1.1	14	$-{0.36}_{-0.09}^{+0.10}$	$-{0.26}_{-0.13}^{+0.14}$	−2.24 ± 0.09	130.79 ± 1.06
J04295950+2433078	CFHT-BD-Tau 20	0	Y	...	2.90 ± 0.17	7	M5	17	$-{0.92}_{-0.29}^{+0.19}$	$-{1.03}_{-0.49}^{+0.35}$	−3.38 ± 0.12	130.72 ± 2.63
J04300399+1813493	UX Tau A	1	N	...	79.00 ± 3.95	7	G8	27	${0.37}_{-0.09}^{+0.05}$	${0.95}_{-0.17}^{+0.13}$	−2.38 ± 0.09	139.40 ± 1.96
J04300399+1813493	UX Tau Ba	2	N	...	<0.36	7	M2	28	$-{0.44}_{-0.10}^{+0.09}$	$-{0.38}_{-0.12}^{+0.13}$	<−4.39	139.40 ± 1.961
J04300399+1813493	UX Tau Bb	3	N	...	<0.36	7	M3.0	7	$-{0.54}_{-0.19}^{+0.10}$	$-{0.50}_{-0.19}^{+0.12}$	<−4.36	139.40 ± 1.961
J04300399+1813493	UX Tau C	4	N	...	<0.36	7	M2.8	14	$-{0.51}_{-0.18}^{+0.09}$	$-{0.47}_{-0.19}^{+0.11}$	<−4.37	139.40 ± 1.961
J04300724+2608207	KPNO 6	0	N	...	<2.40	8	M8.5	19	$-{1.67}_{-0.13}^{+0.17}$	$-{2.20}_{-0.19}^{+0.25}$	<−3.27	116.47 ± 7.46
J04302961+2426450	FX Tau A	1	Y	0.8901	7.84 ± 0.53	7	M1	28	$-{0.35}_{-0.09}^{+0.10}$	$-{0.25}_{-0.13}^{+0.14}$	−3.14 ± 0.09	130.11 ± 0.642
J04302961+2426450	FX Tau B	2	Y	0.8901	<0.36	7	M4	28	$-{0.73}_{-0.19}^{+0.19}$	$-{0.68}_{-0.35}^{+0.19}$	<−4.37	130.11 ± 0.642
J04304425+2601244	DK Tau A	1	Y	2.3603	30.30 ± 0.18	9	K8.5	14	$-{0.20}_{-0.02}^{+0.00}$	$-{0.04}_{-0.03}^{+0.01}$	−2.62 ± 0.08	128.05 ± 0.98
J04304425+2601244	DK Tau B	2	Y	2.3603	2.88 ± 0.19	9	M1.7	14	$-{0.42}_{-0.09}^{+0.10}$	$-{0.34}_{-0.11}^{+0.14}$	−3.57 ± 0.09	128.05 ± 0.981
J04305137+2442222	ZZ Tau AB	−1	N	...	0.59 ± 0.11	7	M3/4.5	23/8	$-{0.24}_{-0.19}^{+0.10}$	$-{0.34}_{-0.24}^{+0.17}$	−4.24 ± 0.11	130.73 ± 1.262
J04305171+2441475	ZZ Tau IRS	0	Y	...	105.80 ± 1.50	8	M4.5	14	$-{0.83}_{-0.23}^{+0.20}$	$-{0.85}_{-0.39}^{+0.26}$	−1.86 ± 0.10	130.73 ± 1.262
J04305718+2556394	KPNO 7	0	N	...	<2.60	8	M8.25	19	$-{1.63}_{-0.14}^{+0.18}$	$-{2.14}_{-0.21}^{+0.26}$	<−3.20	123.09 ± 7.18
J04311444+2710179	JH 56	0	Y	...	<3.10	8	K8.0	14	$-{0.20}_{-0.01}^{+0.01}$	$-{0.03}_{-0.01}^{+0.01}$	<−3.62	127.02 ± 0.72
J04314007+1813571	XZ Tau A	1	Y	0.3001	7.30 ± 0.42	7	M2	16	$-{0.44}_{-0.10}^{+0.09}$	$-{0.38}_{-0.12}^{+0.13}$	−3.05 ± 0.08	144.15 ± 1.552
J04314007+1813571	XZ Tau B	2	Y	0.3001	8.90 ± 0.49	7	M3.5	16	$-{0.62}_{-0.20}^{+0.14}$	$-{0.59}_{-0.26}^{+0.16}$	−2.91 ± 0.09	144.15 ± 1.552
J04315056+2424180	HK Tau A	1	Y	2.3501	33.80 ± 0.20	9	M1	29	$-{0.35}_{-0.09}^{+0.10}$	$-{0.25}_{-0.13}^{+0.14}$	−2.49 ± 0.09	132.85 ± 1.64
J04315056+2424180	HK Tau B	2	Y	2.3501	16.00 ± 0.24	9	M2	29	$-{0.44}_{-0.10}^{+0.09}$	$-{0.38}_{-0.12}^{+0.13}$	−2.78 ± 0.08	132.85 ± 1.641
J04315779+1821380	V710 Tau A	1	Y	3.1701	66.00 ± 3.31	9	M1.7	14	$-{0.42}_{-0.09}^{+0.10}$	$-{0.34}_{-0.11}^{+0.14}$	−2.12 ± 0.09	142.42 ± 2.28
J04315779+1821380	V710 Tau B	2	Y	3.1701	<0.61	9	M3.3	14	$-{0.59}_{-0.20}^{+0.12}$	$-{0.55}_{-0.22}^{+0.14}$	<−4.10	142.42 ± 2.281
J04315968+1821305	LkHa 267	−9	N	...	<0.30	7	M1.7	14	$-{0.42}_{-0.09}^{+0.10}$	$-{0.34}_{-0.11}^{+0.14}$	<−4.39	154.81 ± 3.79
J04321540+2428597	Haro 6-13	0	Y	...	119.60 ± 5.70	8	M0	30	$-{0.25}_{-0.10}^{+0.04}$	$-{0.11}_{-0.14}^{+0.06}$	−2.00 ± 0.08	129.68 ± 0.512
J04321606+1812464	MHO 5	0	N	...	<0.31	7	M6.5	14	$-{1.33}_{-0.17}^{+0.27}$	$-{1.70}_{-0.25}^{+0.45}$	<−4.09	144.06 ± 2.00
J04322210+1827426	MHO 6	0	Y	...	19.37 ± 0.30	11	M5.0	14	$-{0.92}_{-0.29}^{+0.19}$	$-{1.03}_{-0.49}^{+0.35}$	−2.48 ± 0.12	141.38 ± 1.96
J04322415+2251083	J04322415+2251083	−9	N	...	<0.30	7	M4.5	12	$-{0.83}_{-0.23}^{+0.20}$	$-{0.85}_{-0.39}^{+0.26}$	<−4.26	154.76 ± 2.91
J04323028+1731303	GG Tau Aa	1	N	...	7.00 ± 0.87	7	K7	31	$-{0.19}_{-0.01}^{+0.04}$	$-{0.02}_{-0.01}^{+0.07}$	−3.13 ± 0.09	149.46 ± 2.21
J04323028+1731303	GG Tau Ab	2	N	...	<2.40	7	M0.5	31	$-{0.29}_{-0.10}^{+0.07}$	$-{0.17}_{-0.15}^{+0.10}$	<−3.56	149.46 ± 2.211
J04323028+1731303	GG Tau Ba	3	N	...	<2.40	7	M5.5	31	$-{1.05}_{-0.27}^{+0.23}$	$-{1.25}_{-0.45}^{+0.39}$	<−3.29	149.46 ± 2.211
J04323028+1731303	GG Tau Bb	4	N	...	<2.40	7	M7.5	31	$-{1.50}_{-0.17}^{+0.17}$	$-{1.95}_{-0.25}^{+0.25}$	<−3.11	149.46 ± 2.211
J04323058+2419572	FY Tau	1	Y	17.2004	13.80 ± 5.10	8	M0.1	14	$-{0.26}_{-0.10}^{+0.05}$	$-{0.12}_{-0.14}^{+0.07}$	−2.93 ± 0.15	129.74 ± 1.20
J04323176+2420029	FZ Tau	2	Y	17.2004	13.70 ± 2.40	8	M0.5	14	$-{0.29}_{-0.10}^{+0.07}$	$-{0.17}_{-0.15}^{+0.10}$	−2.92 ± 0.11	129.56 ± 1.26
J04324303+2552311	UZ Tau Eab	−1	N	...	128.10 ± 7.30	8	M1/4	20/32	$-{0.05}_{-0.09}^{+0.10}$	$-{0.11}_{-0.18}^{+0.15}$	−1.94 ± 0.10	134.49 ± 7.672
J04324303+2552311	UZ Tau Wa	2	N	...	16.20 ± 3.90	8	M2	16	$-{0.44}_{-0.10}^{+0.09}$	$-{0.38}_{-0.12}^{+0.13}$	−2.77 ± 0.13	134.49 ± 7.672
J04324303+2552311	UZ Tau Wb	3	N	...	31.00 ± 4.10	8	M3	16	$-{0.54}_{-0.19}^{+0.10}$	$-{0.50}_{-0.19}^{+0.12}$	−2.46 ± 0.11	134.49 ± 7.672
J04324911+2253027	IRAS04298+2246Aa	1	Y	1.6505	3.53 ± 0.23	9	K5.5	14	$-{0.11}_{-0.07}^{+0.04}$	${0.11}_{-0.10}^{+0.07}$	−3.38 ± 0.09	163.79 ± 2.14
J04324911+2253027	IRAS04298+2246Ab	2	Y	1.6505	3.06 ± 0.24	9	M4.6	14	$-{0.84}_{-0.22}^{+0.20}$	$-{0.89}_{-0.36}^{+0.28}$	−3.19 ± 0.11	163.79 ± 2.141
J04324911+2253027	IRAS04298+2246Ba	1	N	...	0.25 ± 0.08	9	M8.5	7	$-{1.67}_{-0.13}^{+0.17}$	$-{2.20}_{-0.19}^{+0.25}$	−3.95 ± 0.15	163.79 ± 2.141
J04324911+2253027	IRAS04298+2246Bb	2	N	...	2.30 ± 0.24	9	M8.5	7	$-{1.67}_{-0.13}^{+0.17}$	$-{2.20}_{-0.19}^{+0.25}$	−2.99 ± 0.10	163.79 ± 2.141
J04330622+2409339	GH Tau A	1	Y	0.3101	3.90 ± 0.22	7	M2	16	$-{0.44}_{-0.10}^{+0.09}$	$-{0.38}_{-0.12}^{+0.13}$	−3.42 ± 0.08	129.68 ± 0.512
J04330622+2409339	GH Tau B	2	Y	0.3101	2.90 ± 0.18	7	M2	16	$-{0.44}_{-0.10}^{+0.09}$	$-{0.38}_{-0.12}^{+0.13}$	−3.55 ± 0.09	129.68 ± 0.512
J04330664+2409549	V807 Tau A	1	N	...	8.90 ± 0.46	7	K7	33	$-{0.19}_{-0.01}^{+0.04}$	$-{0.02}_{-0.01}^{+0.07}$	−3.15 ± 0.08	129.68 ± 0.512
J04330664+2409549	V807 Tau Bab	−2	N	...	<0.33	7	M2/2.5	33	$-{0.14}_{-0.10}^{+0.09}$	$-{0.10}_{-0.14}^{+0.12}$	<−4.56	129.68 ± 0.512
J04330945+2246487	J04330945+2246487	0	Y	...	<0.28	7	M6	17	$-{1.22}_{-0.20}^{+0.29}$	$-{1.52}_{-0.31}^{+0.49}$	<−4.08	160.63 ± 3.812
J04331435+2614235	IRAS 04301+2608	−9	N	...	6.60 ± 3.70	8	M0	12	$-{0.25}_{-0.10}^{+0.04}$	$-{0.11}_{-0.14}^{+0.06}$	−2.72 ± 0.26	240.02 ± 65.31
J04331907+2246342	IRAS 04303+2240	−9	N	...	<6.00	8	M0.5	30	$-{0.29}_{-0.10}^{+0.07}$	$-{0.17}_{-0.15}^{+0.10}$	<−3.10	160.63 ± 3.812
J04333278+1800436	J04333278+1800436	−9	N	...	11.00 ± 1.90	8	M1	34	$-{0.35}_{-0.09}^{+0.10}$	$-{0.25}_{-0.13}^{+0.14}$	−2.89 ± 0.11	146.59 ± 1.25
J04333405+2421170	GI Tau	2	Y	13.1006	12.00 ± 1.00	8	M0.4	14	$-{0.28}_{-0.10}^{+0.07}$	$-{0.16}_{-0.15}^{+0.09}$	−2.98 ± 0.09	130.02 ± 0.78
J04333456+2421058	GK Tau	1	Y	13.1006	5.20 ± 0.22	9	K6.5	14	$-{0.18}_{-0.02}^{+0.07}$	${0.00}_{-0.03}^{+0.10}$	−3.39 ± 0.08	128.79 ± 0.73
J04333678+2609492	IS Tau A	1	Y	0.2201	1.15 ± 0.16	7	M0	16	$-{0.25}_{-0.10}^{+0.04}$	$-{0.11}_{-0.14}^{+0.06}$	−3.83 ± 0.10	161.35 ± 2.372
J04333678+2609492	IS Tau B	2	Y	0.2201	1.05 ± 0.16	7	M3.5	16	$-{0.62}_{-0.20}^{+0.14}$	$-{0.59}_{-0.26}^{+0.16}$	−3.74 ± 0.10	161.35 ± 2.372
J04333905+2227207	J04333905+2227207	−9	N	...	31.00 ± 2.00	8	M1.75	12	$-{0.42}_{-0.09}^{+0.10}$	$-{0.35}_{-0.11}^{+0.14}$	−0.93 ± 0.27	810.16 ± 346.28
J04333906+2520382	DL Tau	0	Y	...	168.80 ± 10.80	8	K5.5	14	$-{0.11}_{-0.07}^{+0.04}$	${0.11}_{-0.10}^{+0.07}$	−1.73 ± 0.08	158.62 ± 1.21
J04333935+1751523	HN Tau A	1	Y	3.1403	15.70 ± 0.79	7	K3	14	${0.05}_{-0.08}^{+0.07}$	${0.38}_{-0.14}^{+0.11}$	−2.90 ± 0.08	145.68 ± 0.742
J04333935+1751523	HN Tau B	2	Y	3.1403	0.54 ± 0.10	7	M4.8	14	$-{0.88}_{-0.37}^{+0.19}$	$-{0.95}_{-0.64}^{+0.30}$	−4.03 ± 0.13	145.68 ± 0.742
J04334171+1750402	J04334171+1750402	−9	N	...	6.00 ± 2.00	8	M4	35	$-{0.73}_{-0.19}^{+0.19}$	$-{0.68}_{-0.35}^{+0.19}$	−3.05 ± 0.15	145.74 ± 1.54
J04334465+2615005	J04334465+2615005	−9	N	...	14.11 ± 0.27	11	M5.2	14	$-{0.97}_{-0.27}^{+0.20}$	$-{1.12}_{-0.43}^{+0.39}$	−2.48 ± 0.12	161.35 ± 2.372
J04334871+1810099	DM Tau	0	Y	...	89.40 ± 3.10	8	M3.0	14	$-{0.54}_{-0.19}^{+0.10}$	$-{0.50}_{-0.19}^{+0.12}$	−1.94 ± 0.09	144.55 ± 1.08
J04335470+2613275	IT Tau A	1	Y	2.4103	7.00 ± 0.24	9	K6.0	14	$-{0.15}_{-0.04}^{+0.05}$	${0.05}_{-0.07}^{+0.08}$	−3.08 ± 0.08	161.27 ± 1.97
J04335470+2613275	IT Tau B	2	Y	2.4103	4.17 ± 0.27	9	M2.9	14	$-{0.52}_{-0.19}^{+0.09}$	$-{0.48}_{-0.19}^{+0.11}$	−3.17 ± 0.09	161.27 ± 1.971
J04345542+2428531	AA Tau	0	Y	...	65.00 ± 3.50	8	M0.6	14	$-{0.30}_{-0.10}^{+0.08}$	$-{0.18}_{-0.15}^{+0.11}$	−2.25 ± 0.09	128.78 ± 0.672
J04352020+2232146	HO Tau	0	Y	...	16.20 ± 0.20	9	M3.2	14	$-{0.57}_{-0.20}^{+0.11}$	$-{0.53}_{-0.20}^{+0.13}$	−2.58 ± 0.09	160.67 ± 1.24
J04352737+2414589	DN Tau	0	Y	...	82.30 ± 4.50	8	M0.3	14	$-{0.27}_{-0.11}^{+0.06}$	$-{0.14}_{-0.15}^{+0.09}$	−2.16 ± 0.09	127.76 ± 0.89
J04354093+2411087	CoKu Tau 3 A	1	Y	2.1001	1.84 ± 0.30	9	M0.5	14	$-{0.29}_{-0.10}^{+0.07}$	$-{0.17}_{-0.15}^{+0.10}$	−3.83 ± 0.10	124.85 ± 2.28
J04354093+2411087	CoKu Tau 3 B	2	Y	2.1001	5.79 ± 0.29	9	M4.3	14	$-{0.79}_{-0.21}^{+0.20}$	$-{0.77}_{-0.41}^{+0.22}$	−3.18 ± 0.10	124.85 ± 2.281
J04354733+2250216	HQ Tau	0	Y	...	4.20 ± 2.20	8	K2.0	14	${0.11}_{-0.07}^{+0.04}$	${0.50}_{-0.11}^{+0.07}$	−3.41 ± 0.19	162.54 ± 5.082
J04355277+2254231	HP Tau	0	Y	...	51.70 ± 4.70	8	K4.0	14	$-{0.04}_{-0.06}^{+0.08}$	${0.24}_{-0.12}^{+0.14}$	−2.18 ± 0.09	176.35 ± 3.37
J04355684+2254360	Haro 6-28 A	1	Y	0.6501	5.10 ± 0.29	7	M3.1	14	$-{0.55}_{-0.20}^{+0.10}$	$-{0.51}_{-0.19}^{+0.12}$	−3.07 ± 0.09	162.54 ± 5.082
J04355684+2254360	Haro 6-28 B	2	Y	0.6501	0.78 ± 0.15	7	M3.5	16	$-{0.62}_{-0.20}^{+0.14}$	$-{0.59}_{-0.26}^{+0.16}$	−3.87 ± 0.11	162.54 ± 5.082
J04361030+2159364	J04361030+2159364	0	N	...	<0.31	7	M8.5	17	$-{1.67}_{-0.13}^{+0.17}$	$-{2.20}_{-0.19}^{+0.25}$	<−4.14	118.89 ± 8.68
J04362151+2351165	J04362151+2351165	−9	N	...	1.45 ± 0.12	7	M5.1	14	$-{0.94}_{-0.28}^{+0.20}$	$-{1.07}_{-0.45}^{+0.37}$	−3.78 ± 0.12	115.12 ± 1.70
J04375670+2546229	ITG 1	−9	N	...	<2.30	8	M6	36	$-{1.22}_{-0.20}^{+0.29}$	$-{1.52}_{-0.31}^{+0.49}$	<−1.71	873.64 ± 95.61
J04381486+2611399	J04381486+2611399	0	N	...	0.67 ± 0.10	11	M7.25	13	$-{1.45}_{-0.18}^{+0.20}$	$-{1.89}_{-0.26}^{+0.32}$	−3.70 ± 0.14	147.48 ± 16.01
J04382134+2609137	GM Tau	0	Y	...	1.05 ± 0.07	11	M5.0	14	$-{0.92}_{-0.29}^{+0.19}$	$-{1.03}_{-0.49}^{+0.35}$	−3.77 ± 0.12	137.87 ± 2.86
J04382858+2610494	DO Tau	0	Y	...	108.20 ± 6.90	8	M0.3	14	$-{0.27}_{-0.11}^{+0.06}$	$-{0.14}_{-0.15}^{+0.09}$	−1.97 ± 0.09	138.83 ± 1.02
J04385859+2336351	J04385859+2336351	0	Y	...	10.73 ± 0.18	11	M4.25	37	$-{0.78}_{-0.21}^{+0.20}$	$-{0.75}_{-0.40}^{+0.21}$	−2.91 ± 0.10	126.40 ± 1.92
J04390163+2336029	J04390163+2336029	0	Y	...	0.45 ± 0.10	11	M4.9	14	$-{0.90}_{-0.33}^{+0.19}$	$-{0.99}_{-0.57}^{+0.32}$	−4.22 ± 0.14	127.36 ± 1.30
J04390396+2544264	J04390396+2544264	0	N	...	0.93 ± 0.12	11	M7.25	13	$-{1.45}_{-0.18}^{+0.20}$	$-{1.89}_{-0.26}^{+0.32}$	−3.57 ± 0.12	143.62 ± 4.39
J04391741+2247533	VY Tau A	1	Y	0.6601	1.90 ± 0.22	7	M1.5	14	$-{0.40}_{-0.08}^{+0.10}$	$-{0.32}_{-0.11}^{+0.15}$	−3.57 ± 0.09	158.15 ± 1.212
J04391741+2247533	VY Tau B	2	Y	0.6601	<0.60	7	M4.5	8	$-{0.83}_{-0.23}^{+0.20}$	$-{0.85}_{-0.39}^{+0.26}$	<−3.94	158.15 ± 1.212
J04391779+2221034	LkCa 15	0	Y	...	127.00 ± 4.90	8	K5.5	14	$-{0.11}_{-0.07}^{+0.04}$	${0.11}_{-0.10}^{+0.07}$	−1.85 ± 0.08	158.15 ± 1.21
J04392090+2545021	GN Tau A	1	Y	0.3401	0.47 ± 0.12	7	M2.5	14	$-{0.48}_{-0.14}^{+0.08}$	$-{0.43}_{-0.16}^{+0.11}$	−4.26 ± 0.13	139.23 ± 1.852
J04392090+2545021	GN Tau B	2	Y	0.3401	0.59 ± 0.12	7	M2.5	8	$-{0.48}_{-0.14}^{+0.08}$	$-{0.43}_{-0.16}^{+0.11}$	−4.16 ± 0.11	139.23 ± 1.852
J04393364+2359212	J04393364+2359212	−9	N	...	3.25 ± 0.09	11	M5	12	$-{0.92}_{-0.29}^{+0.19}$	$-{1.03}_{-0.49}^{+0.35}$	−3.35 ± 0.12	126.69 ± 1.64
J04394488+2601527	ITG 15	−9	N	...	3.61 ± 0.10	11	M5.0	14	$-{0.92}_{-0.29}^{+0.19}$	$-{1.03}_{-0.49}^{+0.35}$	−3.24 ± 0.12	136.37 ± 2.08
J04394748+2601407	CFHT 4	0	N	...	2.00 ± 0.50	8	M7	19	$-{1.41}_{-0.18}^{+0.20}$	$-{1.83}_{-0.25}^{+0.31}$	−3.24 ± 0.14	146.82 ± 5.16
J04400067+2358211	J04400067+2358211	0	Y	...	3.13 ± 0.08	11	M6	12	$-{1.22}_{-0.20}^{+0.29}$	$-{1.52}_{-0.31}^{+0.49}$	−3.29 ± 0.14	120.15 ± 2.31
J04400800+2605253	IRAS 04370+2559	0	Y	...	51.70 ± 0.80	8	M2.9	36	$-{0.52}_{-0.19}^{+0.09}$	$-{0.48}_{-0.19}^{+0.11}$	−2.22 ± 0.10	136.66 ± 8.50
J04403979+2519061	J04403979+2519061	−1	N	...	<0.43	10	M5.25/7	13/8	$-{0.68}_{-0.27}^{+0.21}$	$-{1.06}_{-0.39}^{+0.38}$	<−4.16	135.73 ± 0.052
J04404950+2551191	JH 223 A	1	Y	2.1006	1.70 ± 0.14	7	M2.8	14	$-{0.51}_{-0.18}^{+0.09}$	$-{0.47}_{-0.19}^{+0.11}$	−3.69 ± 0.09	139.39 ± 1.08
J04404950+2551191	JH 223 B	2	Y	2.1006	0.76 ± 0.13	7	M6	38	$-{1.22}_{-0.20}^{+0.29}$	$-{1.52}_{-0.31}^{+0.49}$	−3.78 ± 0.15	139.39 ± 1.081
J04410826+2556074	ITG 33A	0	Y	...	4.10 ± 0.23	7	M3	39	$-{0.54}_{-0.19}^{+0.10}$	$-{0.50}_{-0.19}^{+0.12}$	−3.30 ± 0.09	140.48 ± 4.19
J04411078+2555116	ITG 34	0	Y	...	0.70 ± 0.12	7	M5.5	13	$-{1.05}_{-0.27}^{+0.23}$	$-{1.25}_{-0.45}^{+0.39}$	−3.78 ± 0.14	156.54 ± 6.29
J04411681+2840000	CoKu Tau/4 AB	−1	N	...	3.40 ± 1.90	8	M1.1/2.5	8	$-{0.06}_{-0.09}^{+0.10}$	$-{0.04}_{-0.14}^{+0.13}$	−3.50 ± 0.22	138.80 ± 18.703
J04412464+2543530	ITG 40	−9	N	...	1.00 ± 0.12	7	M3.5	24	$-{0.62}_{-0.20}^{+0.14}$	$-{0.59}_{-0.26}^{+0.16}$	−3.90 ± 0.10	138.77 ± 1.192
J04413882+2556267	IRAS 04385+2550	0	Y	...	25.50 ± 2.20	8	M0	40	$-{0.25}_{-0.10}^{+0.04}$	$-{0.11}_{-0.14}^{+0.06}$	−2.61 ± 0.09	139.22 ± 1.282
J04414489+2301513	J04414489+2301513	0	N	...	<0.38	7	M8.5	17	$-{1.67}_{-0.13}^{+0.17}$	$-{2.20}_{-0.19}^{+0.25}$	<−4.03	120.45 ± 5.54
J04414825+2534304	J04414825+2534304	0	N	...	1.34 ± 0.09	11	M7.75	13	$-{1.55}_{-0.15}^{+0.17}$	$-{2.02}_{-0.24}^{+0.24}$	−3.43 ± 0.10	135.81 ± 3.75
J04420777+2523118	V955 Tau A	1	Y	0.3201	2.20 ± 0.17	7	K7	16	$-{0.19}_{-0.01}^{+0.04}$	$-{0.02}_{-0.01}^{+0.07}$	−3.68 ± 0.08	142.25 ± 2.382
J04420777+2523118	V955 Tau B	2	Y	0.3201	0.86 ± 0.14	7	M2.5	16	$-{0.48}_{-0.14}^{+0.08}$	$-{0.43}_{-0.16}^{+0.11}$	−3.98 ± 0.10	142.25 ± 2.382
J04422101+2520343	CIDA 7	0	Y	...	14.50 ± 7.20	8	M5.1	14	$-{0.94}_{-0.28}^{+0.20}$	$-{1.07}_{-0.45}^{+0.37}$	−2.63 ± 0.20	135.70 ± 2.28
J04423769+2515374	DP Tau A	1	Y	0.1105	2.10 ± 0.23	7	M0.8	14	$-{0.33}_{-0.10}^{+0.09}$	$-{0.22}_{-0.14}^{+0.12}$	−3.65 ± 0.09	142.08 ± 1.872
J04423769+2515374	DP Tau B	2	Y	0.1105	1.50 ± 0.21	7	M2	8	$-{0.44}_{-0.10}^{+0.09}$	$-{0.38}_{-0.12}^{+0.13}$	−3.75 ± 0.10	142.08 ± 1.872
J04430309+2520187	GO Tau	0	Y	...	53.20 ± 2.80	8	M2.3	14	$-{0.46}_{-0.12}^{+0.09}$	$-{0.41}_{-0.14}^{+0.12}$	−2.18 ± 0.09	143.98 ± 1.00
J04432023+2940060	J04432023+2940060	0	Y	...	<0.38	7	M5.5	14	$-{1.05}_{-0.27}^{+0.23}$	$-{1.25}_{-0.45}^{+0.39}$	<−3.98	170.46 ± 3.65
J04442713+2512164	IRAS 04414+2506	0	N	...	4.90 ± 0.40	8	M7.25	13	$-{1.45}_{-0.18}^{+0.20}$	$-{1.89}_{-0.26}^{+0.32}$	−2.87 ± 0.11	140.53 ± 2.71
J04455134+1555367	IRAS 04429+1550	−9	N	...	51.00 ± 2.00	8	M2.5	35	$-{0.48}_{-0.14}^{+0.08}$	$-{0.43}_{-0.16}^{+0.11}$	−2.18 ± 0.09	147.38 ± 1.25
J04465305+1700001	DQ Tau AB	−1	N	...	69.30 ± 4.70	8	M0/0	41	${0.05}_{-0.10}^{+0.04}$	${0.19}_{-0.14}^{+0.06}$	−1.95 ± 0.09	196.36 ± 2.01
J04465897+1702381	Haro 6-37 A	1	N	...	2.10 ± 0.34	7	K8.0	14	$-{0.20}_{-0.01}^{+0.01}$	$-{0.03}_{-0.01}^{+0.01}$	−3.42 ± 0.10	195.65 ± 0.862
J04465897+1702381	Haro 6-37 B	2	N	...	<0.96	7	M0.9	14	$-{0.34}_{-0.09}^{+0.10}$	$-{0.23}_{-0.14}^{+0.13}$	<−3.71	195.65 ± 0.862
J04465897+1702381	Haro 6-37 C	3	N	...	38.50 ± 1.95	7	M1	20	$-{0.35}_{-0.09}^{+0.10}$	$-{0.25}_{-0.13}^{+0.14}$	−2.10 ± 0.08	195.65 ± 0.862
J04470620+1658428	DR Tau	0	Y	...	115.20 ± 6.90	8	K6	14	$-{0.15}_{-0.04}^{+0.05}$	${0.05}_{-0.07}^{+0.08}$	−1.70 ± 0.08	194.60 ± 2.46
J04474859+2925112	DS Tau	0	Y	...	16.50 ± 1.80	8	M0.4	14	$-{0.28}_{-0.10}^{+0.07}$	$-{0.16}_{-0.15}^{+0.09}$	−2.67 ± 0.09	158.35 ± 1.12
J04514737+3047134	UY Aur A	1	Y	0.8801	20.80 ± 0.23	9	M0	16	$-{0.25}_{-0.10}^{+0.04}$	$-{0.11}_{-0.14}^{+0.06}$	−2.60 ± 0.08	154.93 ± 1.43
J04514737+3047134	UY Aur B	2	Y	0.8801	7.87 ± 0.25	9	M2.5	16	$-{0.48}_{-0.14}^{+0.08}$	$-{0.43}_{-0.16}^{+0.11}$	−2.95 ± 0.09	154.93 ± 1.431
J04542368+1709534	St 34 Aab	−1	N	...	<4.20	8	M3/3	32	$-{0.24}_{-0.19}^{+0.10}$	$-{0.19}_{-0.19}^{+0.12}$	<−3.35	142.16 ± 1.15
J04542368+1709534	St 34 B	2	N	...	<4.20	8	M5.5	42	$-{1.05}_{-0.27}^{+0.23}$	$-{1.25}_{-0.45}^{+0.39}$	<−3.09	142.16 ± 1.151
J04554535+3019389	J04554535+3019389	0	Y	...	<0.39	7	M4.7	14	$-{0.86}_{-0.36}^{+0.20}$	$-{0.92}_{-0.60}^{+0.29}$	<−4.13	154.12 ± 2.33
J04554801+3028050	J04554801+3028050	2	N	...	<0.35	7	M5.6	13	$-{1.06}_{-0.29}^{+0.22}$	$-{1.25}_{-0.49}^{+0.36}$	<−4.08	156.19 ± 3.73
J04554969+3019400	J04554969+3019400	−9	N	...	<0.35	7	M6	13	$-{1.22}_{-0.20}^{+0.29}$	$-{1.52}_{-0.31}^{+0.49}$	<−4.02	156.05 ± 4.63
J04555605+3036209	XEST 26-062	−9	N	...	0.65 ± 0.14	11	M4.0	14	$-{0.73}_{-0.19}^{+0.19}$	$-{0.68}_{-0.35}^{+0.19}$	−3.96 ± 0.12	156.58 ± 0.862
J04555938+3034015	SU Aur	0	Y	...	27.40 ± 2.50	8	G4	14	${0.49}_{-0.02}^{+0.01}$	${1.32}_{-0.09}^{+0.10}$	−2.83 ± 0.09	157.68 ± 1.48
J04560118+3026348	XEST 26-071	−9	N	...	<0.35	7	M3.1	14	$-{0.55}_{-0.20}^{+0.10}$	$-{0.51}_{-0.19}^{+0.12}$	<−4.27	156.58 ± 0.862
J05030659+2523197	V836 Tau	0	Y	...	29.10 ± 2.40	8	M0.8	14	$-{0.33}_{-0.10}^{+0.09}$	$-{0.22}_{-0.14}^{+0.12}$	−2.36 ± 0.09	168.76 ± 1.24
J05044139+2509544	CIDA 8	0	Y	...	7.70 ± 1.60	8	M3.7	14	$-{0.67}_{-0.20}^{+0.17}$	$-{0.63}_{-0.29}^{+0.18}$	−2.82 ± 0.12	169.99 ± 2.38
J05052286+2531312	CIDA 9 A	1	Y	2.3006	33.80 ± 1.69	7	M1.8	14	$-{0.42}_{-0.09}^{+0.10}$	$-{0.36}_{-0.11}^{+0.14}$	−2.24 ± 0.08	171.08 ± 2.62
J05052286+2531312	CIDA 9 B	2	Y	2.3006	<0.42	7	M4.6	14	$-{0.84}_{-0.22}^{+0.20}$	$-{0.89}_{-0.36}^{+0.28}$	<−4.02	171.08 ± 2.621
J05062332+2432199	CIDA 11	−1	N	...	<0.36	7	M4/4.5	43/8	$-{0.43}_{-0.19}^{+0.19}$	$-{0.46}_{-0.36}^{+0.22}$	<−4.37	138.80 ± 18.703
J05074953+3024050	RW Aur A	1	Y	1.4201	27.20 ± 2.20	8	K0	14	${0.20}_{-0.04}^{+0.08}$	${0.64}_{-0.07}^{+0.14}$	−2.77 ± 0.13	138.80 ± 18.703
J05074953+3024050	RW Aur B	2	Y	1.4201	4.40 ± 0.80	8	K6.5	14	$-{0.18}_{-0.02}^{+0.07}$	${0.00}_{-0.03}^{+0.10}$	−3.40 ± 0.14	138.80 ± 18.703
J05075496+2500156	CIDA 12	0	Y	...	1.16 ± 0.09	11	M3.7	14	$-{0.67}_{-0.20}^{+0.17}$	$-{0.63}_{-0.29}^{+0.18}$	−3.68 ± 0.10	164.15 ± 2.39

Notes.

^aRole values: 0 = verified single, −9 = unknown, 1 = primary, 2 = secondary, 3 = tertiary, 4 = quaternary, −1 = SB primary, −2 = SB secondary. ^bSeparation, flux, and spectral type references: (1) White & Ghez (2001), (2) Kraus & Hillenbrand (2012), (3) Correia et al. (2006), (4) Kraus & Hillenbrand (2009a), (5) Kraus et al. (2011), (6) Kraus & Hillenbrand (2007), (7) This work, (8) Andrews et al. (2013), (9) Paper I, (10) Hardy et al. (2015), (11) Ward-Duong et al. (2018), (12) Furlan et al. (2011), (13) Luhman (2004), (14) Herczeg & Hillenbrand (2014), (15) Briceño et al. (1998), (16) Hartigan & Kenyon (2003), (17) Luhman (2006), (18) Luhman et al. (2003), (19) Briceño et al. (2002), (20) Hartigan et al. (1994), (22) Canty et al. (2013), (23) Cieza et al. (2012), (24) Luhman et al. (2006a), (25) Luhman et al. (2009b), (26) Beck (2007), (27) Espaillat et al. (2010), (28) Duchêne et al. (1999), (29) Monin et al. (1998), (30) White & Hillenbrand (2004), (31) White et al. (1999), (32) Prato et al. (2002), (33) Schaefer et al. (2012), (34) Walter et al. (2003), (35) Luhman et al. (2009a), (36) Luhman et al. (2010), (37) Slesnick et al. (2006), (38) T. L. Esplin et al. (2019, in preparation), (39) Martín (2000), (40) Kenyon et al. (1998), (41) Mathieu et al. (1997), (42) Dahm & Lyke (2011), (43) Kenyon & Hartmann (1995). ^cDistance flag: none: direct Gaia match; 1: used brightest Gaia source within 8'' for companions in multiple systems 2: No Gaia distance or high RUWE, used weighted mean of Gaia distance stars in our sample within 30'; 3: no Gaia detections within 30' in our sample, used median Class II sample Gaia distance and standard deviation of 138.8 ± 18.7 pc.

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For most of our ALMA data, the 3σ non-detection limit is ∼0.35 mJy which corresponds to a total disk mass limit of 4 × 10⁻⁵ M_⊙ = 4 × 10⁻² M_Jup ≈ M_Uranus for a spectral type of M3. Even at this sensitivity level, we have detected no new circumbinary disks, suggesting that circumbinary disks are not a common outcome of the binary star formation process or that they dissipate by an age of 1–2 Myr.

Because our observing strategy was tailored for a large survey and focused on detecting continuum emission, our exposure times are not sufficient to detect CO(2–1) emission from the faint disks that form the majority of our new detections. Of 26 systems where we detect continuum emission (Section 2), we detect CO from only 16 of them, and then usually from only one component in the system, so we are unable to do any meaningful statistical analysis on the CO emission. Nonetheless, since some of our systems do show evidence of CO emission, in the Appendix we provide some brief notes about the detected sources, and we provide peak fluxes and rms values from the integrated CO emission in Table 8.

In order to compare the results from the ALMA survey with the population of Class II stars in Taurus, we need stellar properties for all 211 of the Class II stars. For consistency, we followed the same procedure for all stars, even those not observed by ALMA. First, we compiled spectral types from the literature, trying wherever possible to go to the original references (listed in Table 4) rather than adopting spectral types referenced in other compilations. If the only available reference for a star's spectral type gave a range of types, we adopted the middle of that range, e.g., for a spectral type given as M3–M5 we adopted M4. Using these spectral types, we followed the approach of Ward-Duong et al. (2018) to determine stellar masses and luminosities. More specifically, we converted spectral types to effective temperatures using the scale from Herczeg & Hillenbrand (2014). Two of our sources have spectral type M9.25, while the Herczeg & Hillenbrand (2014) effective temperature scale stops at M9. For these sources, we adopted a simple linear extrapolation of the M7–M9 temperatures, resulting in an adopted effective temperature of 2545 K for these two sources, 25 K cooler than M9. For all sources, we adopted an assumed spectral type uncertainty of ±1 spectral subclass, and translated that into an uncertainty on effective temperature. We then adopted an assumed age of 1 Myr for Taurus, consistent with the finding of Kraus & Hillenbrand (2009b) that 1–2 Myr is a good fit to the cluster sequence. We used that age and the effective temperature to determine a stellar mass and luminosity for each star from the models of Baraffe et al. (2015) for T_eff ≤ 4210 K and the MIST models from Choi et al. (2016) for T_eff > 4210 K. In all cases, we used cubic spline interpolation between tabulated values, and propagated the spectral type uncertainty into the uncertainties we quote for M_⋆ and L_⋆ (Table 4).

As noted above, we included only systems categorized as Class II in assembling the target list for our survey. For binary and multiple systems, the system was included if only one classification was available, as is the case for most close binaries, but we rejected systems where one component has been clearly classified as Class I or Class III. The only multiple systems eliminated by these criteria are T Tau (triple), V773 Tau (triple), UX Tau (quadruple), and 2MASS J04554757+3028077/2MASS J04554801+3028050, a 6'' binary where the primary is a Class III star and both components have no millimeter detection. UX Tau was excluded after the observations were taken, so its data are presented in Tables 2 and 4. To rigorously define a sample for statistical analysis, we consider stellar mass and multiplicity status. The detailed criteria and cutoffs for these categories are described in the subsections below, and Table 5 gives the counts and detection fractions. To standardize our comparisons and analysis, we have assembled fluxes, derived stellar masses and luminosities (Section 3.3), and calculated disk masses for all Class II objects in Taurus, including those that are not included in our statistical sample (Table 4). The flux values come primarily from this work and from the compilation of Andrews et al. (2013), supplemented by more recent ALMA data or limits where available (Hardy et al. 2015; Ward-Duong et al. 2018; Paper I).

Although our input target list was complete in Class II systems to a spectral type of M8, the fact that one of our requested observing blocks was not observed resulted in a substantial number of lower-mass single stars still having 1.3 mm flux upper limits of 1 to ∼20 mJy, significantly worse than the ALMA detections and limits. To avoid biased conclusions from these upper limits, we have defined a stellar mass cutoff above which at least 75% of the stars have been detected. For both single and binary stars, this stellar mass cutoff is 0.06 M_⊙ or a spectral type of M6. In practice, the only binary systems that this eliminates from the statistical sample are FU Tau, an isolated pair of brown dwarfs on the edge of the Taurus cloud (Luhman et al. 2010), and DH Tau, a system where the companion may be of planetary mass (Itoh et al. 2005; Luhman et al. 2006b; Bonnefoy et al. 2014). We did not observe FU Tau with ALMA, and the millimeter upper limits from previous observations of this system are not particularly sensitive, especially given the very low mass of the pair. However, all new observations, regardless of stellar mass, are listed in Tables 2 and 4.

4.2.1. Single-star Sample

4.2.2. Binary and Multiple-star Sample

After applying the definitions of single and binary given above, as well as the stellar mass criteria, we have a sample of 125 stars: 65 single stars, and 60 stars in 30 binary pairs. The millimeter flux detection fraction for this sample is 80% or higher for each category of single, primary, or secondary. This detection fraction is substantially higher than for previous surveys; by comparison, the detection fraction above M6 in Andrews et al. (2013) was 58% and the detection fraction in multiple systems in Harris et al. (2012) was 28%–37%. This detection efficiency gives us more fidelity in comparing the influence of binarity on the millimeter flux and therefore on the disk mass.

To quantitatively compare the properties of the samples, we used the R statistical package, in all cases using routines for censored data to account for the upper limits in millimeter flux. The results from these statistical analyses are given in the following sections. From the survival package we used the log rank test from the survdiff function for two-sample comparisons, and the Kaplan–Meier (KM) maximum likelihood estimator in the survfit function to compare the distribution functions. We used the cenken function to calculate the Kendall's τ correlation coefficient between the primary and secondary disk to stellar mass ratios, and to estimate the slope of any correlation.

As previously shown in several studies in Taurus (Harris et al. 2012; Andrews et al. 2013; Pascucci et al. 2016) the millimeter flux and derived disk mass depend on the stellar mass. We see the same impact of stellar mass with the addition of our ALMA detections and more stringent disk mass limits at lower stellar masses (Figure 6). In applying the two-sample test to the 1.3 mm flux distribution of single, primary, and secondary sources, we see the same results as Harris et al. (2012); the distributions of single and primary star fluxes are similar (p = 0.95), while the secondary fluxes arise from a different sample than the singles (p = 0.027) or the primaries (p = 8.3 × 10⁻³) (Table 6). We also fit a linear regression to the millimeter flux as a function of stellar mass separately for our single-star and binary samples (Figure 7). We followed the same procedure as Andrews et al. (2013), using the LINMIX_ERR MCMC algorithm of Kelly (2007), as implemented in the Python package linmix by Josh Myers. The slopes are consistent with each other and broadly consistent with those found by Andrews et al. (2013) and Pascucci et al. (2016) (1.73${}_{-0.27}^{+0.27}$ for single stars and ${1.93}_{-0.39}^{+0.42}$ for binary stars), but the intercepts of the two samples are clearly different (${1.80}_{-0.18}^{+0.17}$ for the single stars and ${1.26}_{-0.18}^{+0.17}$ for the individual stars in binary systems), with a lower millimeter flux for the stars in binaries at a given stellar mass.

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Table 6.  Two-sample Comparisons

Sample	p-value
	M*	Fν	Mdisk/M*	${M}_{\mathrm{disk}}/{M}_{* }^{1.3}$
Singles/Primaries	3.5 × 10−5	0.95	0.015	0.0089
Singles/Secondaries	0.26	0.027	3.0 × 10−3	0.0037
Primaries/Secondaries	6.3 × 10−5	8.3 × 10−3	0.60	0.98
Singles/Wide	0.0050	0.93	0.18	0.11
Singles/Close	0.037	0.032	1.8 × 10−4	2.3 × 10−4
Wide/Close	0.072	0.034	0.044	0.050

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However, the stellar mass distributions of primary, secondary, and single stars are different from each other, which in turn influences their disk properties. Thus, to fully understand the comparison of single and binary stars, it is important to take into account the underlying stellar populations. For the sample as defined here, including the stellar mass cutoff at M6, the stellar masses for the singles and primaries are drawn from different samples (p = 3.5 × 10⁻⁵, Table 6). This is easily seen in plots of the KM estimator of the cumulative distribution; the single stars span the complete mass range, but the distribution of primary stars has a lower mass cutoff at 0.25 M_⊙ (Figure 8). Unsurprisingly, the distribution of primary stellar masses is also distinct from (and on average larger than) that of secondary stellar masses. There are some differences between the stellar mass distributions between the wide and close binaries, particularly the wide and close secondaries. This difference may be due to the small number of objects in each of our binary separation categories, as a much larger study by Kraus et al. (2011) of 90 Taurus binaries showed no correlation between the mass ratio distribution and the separation distribution.

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While the millimeter flux distribution plots (Figure 9) match previous work (Harris et al. 2012; Andrews et al. 2013), we also looked at other metrics to further investigate the role of stellar mass. Fitting a linear regression to the disk mass as a function of the stellar mass, using the same procedure as for flux above, yields slopes and intercepts of ${1.26}_{-0.26}^{+0.26}$ and −2.32 ± 0.17 for the single stars and ${1.52}_{-0.40}^{+0.41}$ and −2.85 ± 0.18 for the binary stars. These slopes are consistent with Andrews et al. (2013) and, while the slopes are consistent within 1σ, the confidence intervals around the best-fit lines are clearly distinct from each other (similar to what is shown for the fluxes in Figure 7), with the singles having larger typical disk masses at a given stellar mass. We compared the samples of single, primary, and secondary stars for both $\mathrm{log}\left({M}_{\mathrm{disk}}/{M}_{\star }\right)$ and $\mathrm{log}\left({M}_{\mathrm{disk}}/{M}_{\star }^{1.3}\right)$ with the results given in Table 6. For both metrics, the single stars are drawn from a different population than either the primaries or the secondaries, while the primary and secondary stars are consistent with being drawn from the same population. As the statistics are similar between these two metrics, we have used $\mathrm{log}\left({M}_{\mathrm{disk}}/{M}_{\star }\right)$ in our plots to facilitate comparison with works examining other star formation regions such as Chamaeleon (Pascucci et al. 2016). We note that our observed similarity of $\mathrm{log}\left({M}_{\mathrm{disk}}/{M}_{\star }\right)$ for primary and secondary stars is a different result than found in previous work (e.g., Harris et al. 2012). The difference may result from our much higher detection rate among low-mass stars, both among the single stars and the secondaries.

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The previously reported tendency for the disks around primary stars to be brighter than disks around secondaries at millimeter wavelengths is largely an artifact of their greater stellar masses; when the different stellar masses of primaries and secondaries are accounted for, there is no clear difference in the distribution of their disk properties.

Both the two-sample comparison (Table 6) and the KM plots (Figures 9 and 10) show that the millimeter flux and disk mass of wide (>140 au) binaries are much closer to those of single stars than close binaries. This impact on the disk properties of the binary separation has been seen previously (Jensen et al. 1996; Harris et al. 2012). Our more sensitive survey finds that many close binary systems do have disks, but with lower flux than their wider separation counterparts. In Figure 11 we plot the ratio of the secondary to primary disk mass and the total (primary + secondary) 1.3 mm flux as a function of projected separation. In this sample, close binaries tend to have roughly equal mass disks, while wide binaries have a much wider range of disk mass ratios. In both plots, the point size is scaled to the stellar mass ratio, with larger points corresponding to more equal stellar mass ratios. There is no obvious correlation with stellar mass ratio in either of these plots.

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One unresolved question with the smaller flux from binary disks is whether this is due to intrinsically smaller disks, perhaps due to truncation, or to different disk structure. Recent studies by Tripathi et al. (2017) and Andrews et al. (2018) have used resolved disk samples to constrain the contribution of optically thick emission and have confirmed the disk size/luminosity relation previously inferred from smaller samples. These samples were specifically constructed to exclude close binary stars and it would be instructive to compare the disk size between our single and binary samples. However, while our ALMA data for the close binaries have sufficient angular resolution to resolve or constrain the disk size, this is not the case for the majority of the wide binaries and single stars. For instance, of the 66 stars in our singles sample, only 16 have sufficient data to be included in the Andrews et al. (2018) study. Additional high-resolution observations of the complete single and wide binary sample would allow a comparison of disk size with the same categories as our flux comparisons.

In the plot of total system flux as a function of separation (Figure 11), there is a clear trend of higher total flux for larger separations; in our sample, the median flux for the close (15–140 au) binaries is 4.7 mJy, while the median flux for the 140–4200 au binaries is 22.4 mJy. Harris et al. (2012) used different separation divides of <30, 30–300, and >300 au and included pairs from higher-order multiples. Given our sample definition, we only have two systems in their lowest bin, but using the same definitions for the two larger bins, we see roughly the same factor of 5 increase in flux.

In comparing the properties of the primary and secondary circumstellar disks, we note several properties from this sample.

• 1.  
  The two-sample tests indicate that the M_disk/M_⋆ values for primary and secondary stars are consistent with being drawn from the same distribution (p = 0.60). As noted in Section 4.4, both of these samples are drawn from a different population than the single stars for this parameter. The KM plots show that M_disk/M_⋆ is systematically higher for the single stars (Figure 10). Dividing the binaries into wide and close samples instead shows that the wide binaries are closer to the single distribution, but are still systematically lower. Previous studies have shown this negative impact on disk mass for multiple systems (Jensen et al. 1996; Harris et al. 2012; Cox et al. 2017) but here we show that as a function of stellar mass, both the primary and secondary millimeter fluxes and disk masses are systematically lower than for single stars (see also Figure 7).
• 2.  
  It has been shown in previous large studies of Taurus and other star formation regions that, while the disk mass is generally correlated with stellar mass, there is roughly an order of magnitude scatter in disk mass around this relationship (Andrews et al. 2013; Ansdell et al. 2016; Barenfeld et al. 2016; Pascucci et al. 2016). If this scatter is due to physical quantities or processes that vary across the star formation region but are constant on scales of stellar binaries, we would expect the disk mass ratio and the stellar mass ratio in binary systems to be correlated. The left panel of Figure 12 plots this relation for our binary sample, with the diagonal line tracing equal ratios. Consistent with Paper I, these binary systems show no correlation between disk mass ratio and stellar mass ratio, for either wide or close systems. Using the Kendall's τ correlation, the p-value for no correlation is 1 for the wide systems and 0.3 for the close. This lack of correlation can be explained in two ways: (1) The parameters that cause the scatter in the general disk–stellar mass relation vary on scales of less than 30 au or (2) the processes controlling the disk mass in binary formation are different than those for single stars and apply even to binaries with separations much larger than the canonical disk size. We note that the scatter is both above and below the equality line; i.e., for some systems the primary disk is more massive than expected from the stellar mass ratio, while in others the secondary disk is more massive than expected.
• 3.  
  The sensitivity and angular resolution of our ALMA observations have resulted in a much higher detection rate for secondary components than found by previous surveys in Taurus (Harris et al. 2012; Paper I). In these Class II binaries, the primary disk mass does not dominate the total disk mass in the binary system (Figure 11). The average fractional disk mass for the primary compared to the total disk mass in the binary is 62%, with our assumption of optically thin emission. While there are binaries where ${M}_{\mathrm{disk},\mathrm{secondary}}\lt 0.1\,{M}_{\mathrm{disk},\mathrm{primary}}$, there are also three systems where the ratio of the secondary to primary disk mass is significantly (>2σ) higher than one. These systems span the range of projected separations, but in each case the spectral types are at least three sub-classes apart, so the primary and secondary stellar masses are significantly different. These systems contradict the predictions of binary star formation by Bate (2000) that in general, the primary disk will have more mass than the secondary disk; however, these models do not include disk evolution. The three systems are listed here.

  • (a)  
    CZ Tau: Only the secondary disk is detected for CZ Tau and the secondary/primary disk mass limit is >3.1. The position of the source we detect with ALMA has an uncertainty of less than 20 mas (Table 2) and is located at a separation of 0397 and position angle of 875 from the source detected in Gaia DR2 (Gaia Collaboration et al. 2018), to be compared with the separation of 0317 and position angle of 881 ± 11 reported by White & Ghez (2001). If the single Gaia detection is the primary, then the position of the ALMA source agrees well with the expected position of the secondary based on past observations, with a modest separation change due to orbital motion as we see for most other systems in this separation range (Table 3). If Gaia were seeing the secondary, then the source we see with ALMA would be 180° from where the primary should be but coincidentally at the same separation. The spectral types are M3 and M6.
  • (b)  
    CoKu Tau 3: Both components of this binary were detected in Paper I and the spectral types are M0.5 and M4.3. The secondary/primary disk mass ratio is 4.4 ± 1.6.
  • (c)  
    GI/GK Tau: These disks were both detected in previous surveys. GK Tau is the primary with a spectral type of K6.5 while GI Tau has a spectral type of M0.4. The secondary/primary disk mass ratio is 2.5 ± 0.8.
• 4.  
  A different probe of the relationship between the primary and secondary disks is to compare M_disk/M_⋆ within the binary system; i.e., if the primary has a low or high value of M_disk/M_⋆, is that also seen for the secondary? This comparison is shown in the right panel of Figure 12. As can be seen, the wide and close binaries follow different patterns. To confirm this, we used the Kendall's τ relation to test the correlation for the two samples, and the Akritas–Theil–Sen method to find the estimated slope, again using the R routine cenken. The slopes and correlation coefficients τ are given in Table 7, where τ = 0 corresponds to no correlation and the p-value is reported for no correlation being present (i.e., a low p-value represents the presence of a correlation). For all binaries, there is no correlation between the primary and secondary ratios (τ = 0.08, p = 0.53). Analyzing the wide and close samples separately, the τ and p-values indicate there is a correlation. However, while the close binaries are positively correlated, the wide binaries are negatively correlated. That is, in wide binary systems, if the primary has a high value of M_disk/M_⋆, the secondary preferentially has a low value of M_disk/M_⋆. One possible explanation is that if close binaries have disks that accrete from a common envelope, whatever mechanism controls the division of mass between the disk and the star operates similarly for both stars. On the other hand, for the wider binaries, the mass accretion process may be competitive, and if the primary disk receives more mass relative to the star, this could result in less relative disk mass for the secondary.

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