Spectroscopic Follow-up of Discoveries from the NEOWISE Proper Motion Survey

Spectra of 59 objects were obtained using the SpeX spectrograph (Rayner et al. 2003) on the NASA Infrared Telescope Facility (IRTF) on Mauna Kea. Observations were conducted between the dates of UT 2016 February 24 and UT 2017 November 22 (see Table 1 for full list of observation dates). The data were collected in prism mode spanning a wavelength range of 0.8–2.5 μm with a resolution of $R\equiv \lambda$/$\bigtriangleup \lambda =250$, using either the 05-wide slit or the 03-wide slit aligned to the parallactic angle. For each object, a series of exposures were taken using an ABBA nod pattern along the 15'' long slit. Additionally, an A0 V star was observed at a similar airmass to each object and used for telluric correction and flux calibration. The data were all reduced using the Spextool package (Vacca et al. 2003; Cushing et al. 2004).

In order to determine the spectral type of our subdwarf candidates, we require spectra of subdwarf standards. One of us (A.J.B) obtained spectra of 16 M and L subdwarf standards using IRTF/SpeX. Observations were conducted between the dates of UT 2003 September 17 and UT 2006 December 21. Data were collected in prism mode, as discussed above, and reduced using the Spextool package (Vacca et al. 2003; Cushing et al. 2004). A list of these standards, their spectral types, the references for those spectral types, and the details of those observations are listed in Table 2. Spectra of these objects are shown in Figure 7.

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Spectra of five objects were obtained with the Folded-Port Infrared Echellete (FIRE; Simcoe et al. 2013) spectrograph on the Magellan 6.5 m Baade Telescope at Las Campanas Observatory. Observations were conducted on UT 2016 July 18. All observations were made with the high-throughput prism mode, which achieved a resolving power of R ∼ 450 across the 0.8–2.45 μm range. We used the 06-wide slit, aligned to the parallactic angle, and took exposures at two different nod positions along the slit. For all science targets, the sample-up-the-ramp mode was used. A0 V stars were observed after each science target to correct for telluric absorption and flux calibration. Data reduction was performed using a modified version of the Spextool reduction package (Vacca et al. 2003; Cushing et al. 2004).

One object was observed on UT 2016 December 9 with Astronomy Research using the Cornell Infrared Imaging Spectrograph (ARCoIRIS) on the 4 m Blanco telescope located at the Cerro Tolo Inter-American Observatory (CTIO). ARCoIRIS takes simultaneous spectra across six cross-dispersed orders covering the 0.8–2.4 μm range, with a resolving power of ∼3500. Science exposures were taken at two different nod positions along the slit, which has a fixed width of 1''. After observing our science target, we observed an A0 V star to use for telluric corrections and flux calibration. Data reduction was performed using a modified version of the Spextool reduction package (Vacca et al. 2003; Cushing et al. 2004).

Spectral types were determined by comparing each spectrum to the near-infrared spectral standards from Kirkpatrick et al. (2010) and the near-infrared M and L subdwarf standards given in Table 2. First, the standard and object spectra were normalized to unity between 1.27 and 1.29 μm. One of us (J.J.G.) then assigned spectral types by eye, based on which spectral standard was the best match to each object over the 0.9–1.4 μm wavelength range. Some spectra fall appreciably red or blue of the spectral standards in the H- and K-bands and these are typed as red or blue, respectively. Another one of us (A.C.S.) confirmed all spectral types by eye, and the results are listed in Table 3.

In total, we present spectra of 31 new M dwarfs, 18 new L dwarfs, and 11 new T dwarfs. Spectra of one additional L dwarf and four additional T dwarfs are also presented, but these have been previously published as discussed below. Thirteen of our objects are subdwarfs, including nine new M subdwarfs and four new L subdwarfs. Eleven of these objects (including two subdwarfs) with spectral types ranging from M7 to T7 are predicted to be within 25 pc.

Five of our 65 objects have previously published spectra. Best et al. (2015) published a spectrum of WISE 0135+0205 (PSO J023.8557+02.0884), classifying it as an L9.5. We classified it as T0 (sl. red). Best et al. (2015) observed WISE 0316+2650 (PSO J049.1159+26.8409), classifying it as T2.5, with strong potential of being a binary. We classified it as a T3. Tinney et al. (2018) published a spectrum of WISE 1735−8209, classifying it as a T8; we classify it as a T7. Luhman & Sheppard (2014) observed WISE 2111−5211, classifying it as a T2.5; we typed it as a T3. Best et al. (2015) observed WISE 2249−1627 (PSO J342.3797−16.4665), classifying it as an L5, possibly in a binary with a T dwarf. Robert et al. (2016) also observed this object, classifying it as an L4/T1 binary. We classified this as an L5 (blue).

Additionally, two objects have published spectral types estimated using photometry. Tinney et al. (2018) used methane imaging to spectral type WISE 0309−5016 as a T7, which agrees with our spectral type. Kirkpatrick et al. (2019) note that, because this object is much brighter in M_H than other objects of similar H − W2 color, and much brighter in M_W1 and ${{\rm{M}}}_{\mathrm{ch}1}$ than other objects of similar Spitzer ch1−ch2 color, it is likely an unresolved binary. Kirkpatrick et al. (2019) estimated the spectral type of WISE 0323−5907 based on Spitzer ch1 and ch2 photometry to be a T6. We classified this object as a T7.

Finally we note that, in Table 10 of Schneider et al. (2016), the spectral type of WISE 0413+2103 was mistaken for that of WISE 0413−2023. This caused WISE 0413+2103 to be listed as a late-type candidate, when it is in fact an M dwarf. We noticed this while selecting our follow-up candidates, and so observed WISE 0413−2023, which has a spectral type of L5 (blue).

We can improve upon the spectrophotometric distances of Schneider et al. (2016) using available photometry and absolute magnitude–spectral type relations to compute spectroscopic distances for each of our objects. We primarily used the relations of Dupuy & Liu (2012), which are valid for objects with spectral types between M6 and T9 (inclusive) and can be used with Two Micron All Sky Survey (2MASS) J, H, and K_s and WISE W1 and W2 photometry. For spectral types earlier than M6, we used the relations of Zhang et al. (2013), which are valid for spectral types between M1 and L9 (inclusive) and can be used with 2MASS J, H, and K_s photometry. Finally, for the subdwarfs, we used the relations of Zhang et al. (2017), which are valid for subdwarfs with spectral types between M0 and L7 (inclusive) and can be used with 2MASS J- and H-band photometry.

These relations were combined with available photometry to calculate the distances and their uncertainties using a Monte Carlo approach to properly account for the uncertainties in the spectral type, spectral type–absolute magnitude relation, and the photometry. We randomly drew from distributions for the spectral type, the absolute magnitude, and the apparent magnitude to compute a distance. A uniform distribution with a width of 1 subtype centered on the spectral type of the object was used for the spectral type distribution, a normal distribution with a mean and standard deviation given by the spectral type–absolute magnitude relation and rms uncertainty of that relation was used for the absolute magnitude relation, and a normal distribution with a mean and standard deviation given by the apparent magnitude and its uncertainty was used for the apparent magnitude distribution. The process was repeated 10,000 times for each object, and the mean and standard deviation of the resulting distribution gave us the spectroscopic distance and its uncertainty. Distances and uncertainties were calculated for each object in the filters where the spectral type–absolute magnitude relations are valid, and a weighted average of all individual spectroscopic distances for each object was then used to calculate the final spectroscopic distances, which can be found in Table 4.

Table 4.  Object Distances

AllWISE Designation	Spectrala	Schneider 2016b	Our	Gaia Sourcec	Gaiad	Kirkpatrick 2018e
	Type	Dist (pc)	Dist (pc)	ID	Dist (pc)	Dist (pc)
J000430.66−260402.3	T2 (blue)	⋯	25 ± 2.3	⋯	⋯	⋯
J000458.47−133655.1	T2	⋯	29 ± 2.7	⋯	⋯	⋯
J000536.63−263311.8	T0 (pec)	⋯	31 ± 2.6	⋯	⋯	⋯
J000856.39−281321.7	L8	24–34	29 ± 2.5	⋯	⋯	⋯
J010134.83+033616.0	M7	⋯	92 ± 7.7	2551477793805008256	${86}_{-5.1}^{+5.8}$	⋯
J010631.20−231415.1	L9	⋯	36 ± 3.2	⋯	⋯	⋯
J011049.18+192000.1	M8	⋯	59 ± 4.9	2786913366801779968	${51.5}_{-0.95}^{+0.98}$	⋯
J013525.38+020518.2	T0 (sl. red)	⋯	25 ± 2.1	⋯	⋯	⋯
J022721.93+235654.3	L9	22–31	28 ± 2.3	⋯	⋯	⋯
J030119.39−231921.1	T1 (sl. blue)	24–33	27 ± 2.3	⋯	⋯	⋯
J030919.70−501614.2	T7	9–13	14 ± 1.8	⋯	⋯	15.0 ± 0.87
J031627.79+265027.5	T3	⋯	22 ± 2.1	⋯	⋯	⋯
J032309.12−590751.0	T7	16–26	19 ± 2.2	⋯	⋯	14.0 ± 0.84
J032838.73+015517.7	L5 (blue)	⋯	47 ± 4.5	⋯	⋯	⋯
J033346.88+385152.6	M8	⋯	104 ± 8.7	236441149397820800	${85}_{-7.2}^{+8.6}$	⋯
J034409.71+013641.5	L8	⋯	37 ± 3.5	⋯	⋯	⋯
J034858.75−562017.8	T3	24–33	28 ± 3.0	⋯	⋯	⋯
J041353.96−202320.3	L5 (blue)	⋯	41 ± 3.5	⋯	⋯	⋯
J041743.13+241506.3	T6	13–19	12 ± 1.0	⋯	⋯	⋯
J053424.45+165255.0	L2 (pec)	18–25	33 ± 2.8	3397015189186833408	${28}_{-2.8}^{+3.6}$	⋯
J054455.54+063940.3	M9	24–37	35 ± 2.9	3333278694852547328	${31.3}_{-0.35}^{+0.36}$	⋯
J061429.77+383337.5	M9	18–27	27 ± 2.2	956200977271782144	${25.2}_{-0.23}^{+0.24}$	⋯
J062858.69+345249.2	L4	⋯	40. ± 3.3	⋯	⋯	⋯
J063552.52+514820.4	T0	⋯	29 ± 2.7	⋯	⋯	⋯
J084254.56−061023.7	T4	20–29	21 ± 1.9	⋯	⋯	⋯
J085039.11−022154.3	sdL7 (red)	21–30	24 ± 3.4	⋯	⋯	⋯
J085633.87−181546.6	L1	⋯	64 ± 5.4	5728941156831133952	${56}_{-3.5}^{+4.0}$	⋯
J092453.76+072306.0	M6	⋯	140 ± 12	586424457955450496	${118}_{-7.3}^{+8.3}$	⋯
J094812.21−290329.5	sdL1	⋯	71 ± 9.8	5656672112963964928	${62}_{-2.6}^{+2.8}$	⋯
J095230.79−282842.2	esdM4	⋯	110 ± 15	5464936251656505344	$130{.}_{-2.5}^{+2.6}$	⋯
J101944.62−391151.6	T3 (blue)	19–28	23 ± 2.0	⋯	⋯	⋯
J103534.63−071148.2	sdL7	⋯	42 ± 6.1	⋯	⋯	⋯
J111320.39+501010.5	M4 (blue)	⋯	140 ± 19f	838162769031557888	${181}_{-9.3}^{+10.4}$	⋯
J112158.76+004412.3	M7 (blue)	⋯	116 ± 9.9	3798149260432886528	${75}_{-6.7}^{+8.2}$	⋯
J112859.45+511016.8	L3	⋯	46 ± 3.8	⋯	⋯	⋯
J120751.17+302808.9	M8	⋯	78 ± 6.5	4014105473115624192	${71}_{-3.5}^{+3.9}$	⋯
J121231.97−050750.7	M7 (sl. blue)	⋯	71 ± 6.0	3596616230830390016	${66}_{-1.8}^{+1.9}$	⋯
J121914.75+081027.0	sdM7	⋯	120 ± 16	3902112585964749312	${122}_{-7.5}^{+8.5}$	⋯
J122042.20+620528.3	sdM7	⋯	88 ± 7.4	1583395326382043392	${113}_{-4.0}^{+4.3}$	⋯
J123513.87−045146.5	esdM4	⋯	160 ± 22	3680363115235579904	${156}_{-4.9}^{+5.2}$	⋯
J124516.66+601607.5	sdM8.5	⋯	100 ± 14	1579775596664490752	${116}_{-3.7}^{+4.0}$	⋯
J133520.09−070849.3	M7	⋯	130 ± 11	3630793763800277376	$100{.}_{-9.4}^{+11}$	⋯
J134359.71+634213.1	M8	⋯	98 ± 8.3	1665037775596252544	$80{.}_{-5.8}^{+6.8}$	⋯
J143942.79−110045.4	sdL1	⋯	80. ± 11	6324908688520221568	${130}_{-26}^{+47}$	⋯
J144056.64−222517.8	sdM8.5	⋯	80. ± 11	6278872445902622336	${106}_{-3.8}^{+4.0}$	⋯
J145645.54−103343.5	M8 (sl. blue)	⋯	61 ± 5.0	6313890619936907136	${49}_{-1.3}^{+1.4}$	⋯
J145747.55−094719.3	esdM4	⋯	140 ± 19	6326026685686833920	${166}_{-5.5}^{+5.9}$	⋯
J155225.22+095155.5	sdM7	⋯	130 ± 18	4455454422667645184	${130}_{-12}^{+14}$	⋯
J165057.66−221616.8	M5	22–35	41 ± 6.4	4126600390415016832	${34.7}_{-0.12}^{+0.12}$	⋯
J171059.52−180108.7	M4 (blue)	24–37	60 ± 12	4134686886136743552	${44.2}_{-0.17}^{+0.18}$	⋯
J171105.08−275531.7	M6	21–34	33 ± 2.8	⋯	⋯	⋯
J171454.88+064349.8	L2 (red)	⋯	56 ± 4.8	⋯	⋯	⋯
J173551.56−820900.3	T7	14–21	13 ± 1.4	⋯	⋯	13.3 ± 0.81
J180839.55+070021.7	L1 (blue)	⋯	79 ± 6.7	⋯	⋯	⋯
J182010.20+202125.8	sdM8.5	⋯	80. ± 11	4528661276939071488	${124}_{-3.0}^{+3.1}$	⋯
J183654.10−135926.2	M6	20–31	35 ± 3.0	⋯	⋯	⋯
J191011.03+563429.3	M8	16–23	29 ± 2.4	2141364423410899968	${23.48}_{-0.07}^{+0.07}$	⋯
J201252.78+124633.3	M7 (sl. red)	17–26	20. ± 1.7	1803225427774999680	${19.27}_{-0.03}^{+0.03}$	⋯
J211157.84−521111.3	T3	⋯	26 ± 2.4	⋯	⋯	⋯
J215550.34−195428.4	L7	⋯	39 ± 3.6	⋯	⋯	⋯
J221737.41−355242.7	M5	⋯	150 ± 24	⋯	⋯	⋯
J223444.44−230916.1	L5	⋯	55 ± 5.2	⋯	⋯	⋯
J224931.10−162759.6	L5 (blue)	⋯	37 ± 3.1	⋯	⋯	⋯
J230743.63+052037.3	M7	⋯	64 ± 5.4	2662702873947256832	${87}_{-2.7}^{+2.9}$	⋯
J234404.85−250042.2	M7	⋯	84 ± 7.2	2338610933917661696	${63}_{-5.1}^{+6.0}$	⋯

Notes.

^aSpectral types as determined by comparing our SpeX Prism spectra with spectral standards. Subdwarf spectral types are denoted by the following abbreviations: sd = subdwarf, d/sd = dwarf/subdwarf, and esd = extreme subdwarf. ^bOnly listed for objects that were nearby candidates in the Schneider et al. (2016) survey. ^cOnly listed for objects with matches in Gaia DR2. ^dTaken from Bailer-Jones et al. (2018). ^eOnly listed for three objects, which were included in Kirkpatrick et al. (2019). ^fThis is the distance we calculated, assuming this object is a subdwarf. In the absence of this assumption, the distance would be 260 ± 31 pc.

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Most of our distances are within, or close to, the distance ranges from the Schneider et al. (2016) survey. WISE 1710−1801 shows a large discrepancy between the spectroscopic distance calculated in this paper (60 ± 12 pc) and the spectrophotometric distance estimated in Schneider et al. (2016; 24–37 pc). This is likely a result of the fact that Schneider et al. (2016) used the Dupuy & Liu (2012) relations to calculate their distance estimate, and these relations are not valid for early M dwarfs. The estimate in this paper used the Zhang et al. (2013) relations, which are valid for early M dwarfs.

We also searched the Gaia DR2 archive to identify which of our candidates were detected by Gaia. Using the 2MASS–AllWISE proper motions calculated by Schneider et al. (2016), and the positions of our sources from the AllWISE epoch (2010.5), we calculated the positions of each of our sources in the Gaia epoch (2015.5). It was not possible to do this for WISE 0309−5016, because it was not detected in 2MASS and Schneider et al. (2016) were not able to calculate a 2MASS–AllWISE proper motion for it. We then cross-matched the positions of our objects at the Gaia epoch against the Gaia DR2 archive, and identified all Gaia matches within 5''. We then examined all the matches for each object to confirm matches, and in some cases, determine which of the multiple matches was the correct object. This was accomplished by: first, performing a visual inspection of each of our objects using finder charts, examining the position of our object in images from Digitalized Sky Survey (DSS), UKIRT InfraRed Deep Sky Surveys (UKIDSS), 2MASS, WISE, and Pan-STARRs, where available. Second, the separation was calculated between the coordinates we calculated for each object at the Gaia epoch and the coordinates for each match in the Gaia DR2 catalog to determine which of the multiple matches was closest to the coordinates we calculated. Third, we compared the proper motions for each match in the Gaia catalog to the proper motions for each source calculated in Schneider et al. (2016) to make sure those values matched.

In total, 32 of our 65 objects have matches in Gaia. They are all listed in Table 4, along with the Gaia source ID for each match, and the Gaia distances for each object (Bailer-Jones et al. 2018). Two of our objects (WISE 0850−0221 and WISE 1808+0700) had matches in the Gaia catalog with no parallax measurements, and so are not included in Table 4. For most of our objects, we find good agreement between our spectroscopic distances and the Gaia distances, as well as the 2MASS–AllWISE proper motions and the Gaia proper motions, as can be seen in Figure 8. For WISE 1113+5010, we noticed a large discrepancy between our spectroscopic distance of 260 ± 31 pc and the Gaia distance of ${181}_{-9.3}^{+10.4}$ pc. Our spectral type for this object is an M4 (blue), meaning it exhibits suppressed flux in the H- and K-bands, relative to the J-band, causing it to appear bluer in the H- and K-bands than the field objects of the same spectral class. This is typically an indicator that an object could be a subdwarf (this is discussed in greater detail in Section 5.3). If we use the absolute magnitude–spectral type relations for subdwarfs, we get a distance of 140 ± 19 pc, which is much closer to the Gaia distance. This suggests that WISE 1113+5010 may either be a subdwarf (sdM4) or an intermediate subdwarf (d/sdM4). Unfortunately, we do not have a spectrum of a sdM4 standard, and so we cannot confirm this hypothesis.

Included in Table 4 along with our Gaia distances, are distances for three objects (WISE 0309−5016, WISE 0323−5907, and WISE 1735−8209) calculated from parallaxes obtained by Kirkpatrick et al. (2019) using the Infrared Array Camera (IRAC; Fazio et al. 2004) on the Spitzer Space Telescope (Werner et al. 2004). The distances for WISE 0309−5016 and WISE 1735−8209 agree very well with the spectroscopic distances we calculated, but the distance for WISE 0323−5907 does not, as can be seen in Figure 8. The parallax from Kirkpatrick et al. (2019) gives a distance of 14.0 ± 0.84 pc, and our spectroscopic distance is 19 ± 2.1 pc. The reason for the large discrepancy is still unclear. Kirkpatrick et al. estimate the spectral type of this object to be T6, based on the ch1−ch2 photometry but, according to our spectrum from IRTF/SpeX, it is a textbook T7. Kirkpatrick et al. note that this source is too faint in W1 and W2 for its Spitzer ch1−ch2 color. If we calculate the distance using only the 2MASS J-band photometry (which comes from the 2MASS reject catalog), we get a distance of 18.1 ± 4.2 pc, which falls within 1σ of the Kirkpatrick et al. value. This object will need to be studied further to determine the exact reason for this discrepancy.

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Volume-limited samples are the gold standard in astrophysics because they provide an unbiased sample of the objects under scrutiny. Constructing a complete census of the stars and brown dwarfs in the solar neighborhood is particularly important because this region contains the brightest, and thus most easily studied, objects of a given spectral class. At least one star or brown dwarf has been added to the list of stellar systems that lie within 10 pc of the Sun every year since 2002 (Henry et al. 2018) indicating that the local census remains incomplete. The intrinsic faintness of brown dwarfs makes constructing volume-limited samples difficult, particularly out to larger distances where the census is even more incomplete.

Our survey and follow-up observations have identified 21 new objects within 30 pc of the Sun. Eleven of these objects have distances within 25 pc: one M dwarf (WISE 2012+1246 M7; sl. red), nine T dwarfs (WISE 0004−2604 T2 (blue), WISE 0135+0205 T0 (sl. red), WISE 0309−5016 T7, WISE 0316+2650 T3, WISE 0323−5907 T7, WISE 0417+2415 T6, WISE 0842−0610 T4, WISE 1019−3911 T3 (blue), and WISE 1735−8209 T7), and one L subdwarf (WISE 0850−0221 sdL7; red). An additional 10 objects have spectroscopic distances of 25 pc < d < 30 pc: two M dwarfs (WISE 0614+3833 M9 and WISE 1910+5634 M8), two L dwarfs (WISE 0008−2813 L8 and WISE 0227+2356 L9), and six T dwarfs (WISE 0004−1336 T2, WISE 0301−2319 T0 (sl. blue), WISE 0328−5620 T3, WISE 0348−5620 T3, WISE 0635+5148 T0, and WISE 2111-5211 T3). Three of our objects are within 15 pc. All three of these are T dwarfs: (WISE 0309−5016 (13.8 ± 1.69; T7), WISE 1735−8209 (12.4 ± 1.28; T7), and WISE 0417+2415 (11.4 ± 0.96; T6)). Even though it is within 15pc, WISE 0417+2415 has no published parallax. The other two have parallaxes published in Kirkpatrick et al. (2019).

While the stellar mass function in the solar neighborhood is well understood (Bastian et al. 2010), the substellar mass function has proven more difficult to measure for two reasons. First, brown dwarfs cool over time, and thus do not follow a mass–luminosity relation as stars do. Second, as mentioned in Section 5.1, the census of brown dwarfs in the solar neighborhood remains incomplete. The census is most incomplete for the late-type T and Y dwarfs because of their intrinsic faintness. However, these objects are among the most important because it has been shown that they provide the best constraints on the underlying mass function (e.g., Burgasser 2004 and Kirkpatrick et al. 2019).

In an effort to identify new late-type objects in the solar neighborhood, we observed 23 candidate late-type objects (≥L7) from Schneider et al. (2016). Fourteen of these are T dwarfs, with spectral types ranging from T0 to T7; four are late-type L dwarfs; and one (WISE 1035−0711) is an sdL7. The remaining four were mid-L dwarfs, with spectral types of either L4 or L5. We also discovered three additional late-type objects: WISE 2155−1954 (L7), WISE 0004−1336 (T2), and WISE 0850−0221 (sdL7; red), which were not late-type candidates.

WISE 0004−1336 was one of the objects we observed to fill in gaps in our R.A. coverage (see Section 2). In Schneider et al. (2016) it had an estimated spectral type, based on the available photometry, of L6.9, making it just beyond the L7 cutoff, so it was not listed as one of their late-type candidates. When we observed this object, we found it to have a spectral type of T2. Three other objects (WISE 0005−2633, WISE 0135+0205, and WISE 0635+5148) also had estimated spectral types, based on photometry, of L7 or earlier, and were classified as T dwarfs based on their spectra. In Schneider et al. (2016), the spectral types for these objects were estimated based on their infrared colors (see the Appendix of Schneider et al. 2016 for details), using available photometry. The colors for early T dwarfs can overlap with the colors of mid- to early-L dwarfs (see Figure 5 in Schneider et al. 2016), which can cause these objects to be mistakenly classified as mid-L dwarfs because of the similarity in color. It is likely that this is why these objects were misclassified as L6 or L7, instead of T dwarfs, and why WISE 0004−2604 missed the cutoff for the late-type objects in Schneider et al. (2016).

While effective temperature is the primary parameter that controls the spectral morphology of brown dwarfs, both surface gravity and metallicity also play a role. Our understanding of the impacts that variations in metallicity have on the emergent spectra of brown dwarfs is still in its infancy because of the paucity of metal-poor L and T dwarfs known; the total number currently stands at 71 (Zhang et al. 2018) which is in stark contrast to the thousands of near-solar-metallicity brown dwarfs known. Identifying new metal-poor brown dwarfs will help us to build a large enough sample to begin inferring trends in spectral morphology within a given spectral type, and will allow us to better examine trends across a larger range of subdwarf types.

We conducted follow-up observations of 24 candidate subdwarfs from Schneider et al. (2016). As described in Section 3.1, we have spectra of 16 M and L subdwarf standards, obtained with IRTF/SpeX, which we used to determine which of our objects were subdwarfs. While this is the first time these have been used as near-infrared subdwarf standards, all had previously been spectral typed as subdwarfs in the optical, as detailed in Table 2. Our subdwarf spectral standards include both sd and esd for the M spectral class, and sd for the L spectral class. The esd have −1.7 < [Fe/H] ≤−1.0, and the sd have −1.0 < [Fe/H] ≤ −0.3 (Gizis 1997; Zhang et al. 2017). All of our observed objects, both subdwarf candidates and non-subdwarf candidates, were compared against both the subdwarf and non-subdwarf standards during the spectral typing process. Final spectral types were determined based on the best match between each object and all available spectral standards. As can be see in Table 2 and Figure 7, our spectral sequence of subdwarf standards is incomplete, especially for the L subdwarfs. This is due to the fact that, at present, there are very few near-infrared spectral standards for subdwarfs available. We have spectral typed our objects to the best of our ability with the available standards, but, we have likely missed some of the subdwarfs in our sample, as a result of not having standards at those spectral types.

Of the 24 subdwarf candidates we observed, 11 were spectral typed as subdwarfs: six sdM (WISE 1219+018 sdM7, WISE 1220+6205 sdM7, WISE 1245+6016 sdM8.5, WISE 1440−2225 sdM8.5, WISE 1552+0951 sdM7, and WISE 1820+2021 sdM8.5), two sdL (WISE 0948−2903 sdL1 and WISE 1439−1100 sdL1), and three esdM4 (WISE 0952−2828, WISE 1235−0451, and WISE 1457−0947). Ten of the remaining 13 were spectral typed as M dwarfs, with spectral types ranging from M4 to M8, one is an L1 (blue), (WISE 1808+0700) and one is a T7 (WISE 0323−5907). The remaining object, WISE 1019−3911, was spectral typed as a T3 (blue). We also observed two objects that were not subdwarf candidates, but were spectral typed as subdwarfs. Both are L subdwarfs. WISE 0850−0221 is a sdL7 (red) and WISE 1035−0711 is a sdL7. According to Zhang et al. (2018), there are 66 known L subdwarfs. This includes four sdL7s, three sdL5s, and four sdL1. We have discovered two additional sdL7s, two additional sdL1s, and three candidate sdL5s, substantially increasing the number of known L subdwarfs at these spectral types.

Due to enhanced collision-induced H₂ absorption, subdwarfs tend to have suppressed flux in the H- and K-bands, relative to the J-band, causing them to appear bluer in the H- and K-bands than the field objects of the same spectral class. In addition, they exhibit brightening in the Y-band. Among the objects we observed, 11 are blue: four M dwarfs, four L dwarfs, and three T dwarfs. For three of these (WISE 1121+0044, M7 (blue), WISE 1456−1033 M8 (sl. blue), and WISE 1808+0700 L1 (blue)), we have subdwarf spectral standards at those spectral types and so can confirm that, while they are blue, they are not subdwarfs. For the remaining eight, we do not. We believe these objects could be subdwarf candidates, but without subdwarf standards at the corresponding spectral types, we cannot be certain at this time. We have three new candidate T subdwarfs: WISE 0301−2319 (sdT1), WISE 0004−2604 (sdT2), and WISE 1019−3911 (sdT3); three new candidate sdL5: WISE 0328+0155, WISE 0413−2023, and WISE 2249−1627; and two new candidate sdM4: WISE 1113+5010 and WISE 1710−1801.

Additionally, WISE 0948−2903 (sdL1), WISE 1439−1100 (sdL1), and some of the blue late Ms (e.g., WISE 1212−0507 and WISE 1121+0044) show a triangular H-band peak, a feature that is seen in the spectra of young, low-gravity M and L dwarfs and attributed to reduced collision-induced H₂ absorption in low pressure atmospheres (e.g., Rice et al. 2011; Allers & Liu 2013). Aganze et al. (2016) analyzed this feature while studying the d/sdM7 GJ 660.1B which has [Fe/H] = −0.63 ± 0.06, and found that this feature is also indicative of subsolar metallicity. The presence of this feature in our spectra supports the classification of WISE 0948−2903 and WISE 1439−1100 as subdwarfs, and suggests that the blue M dwarfs may also have subsolar metallicities.

Among our discoveries, we find three new T subdwarf candidates all with distances around 25 pc. One of these, WISE 1019−3911, was listed as a candidate in all three categories. Based on the estimates from Schneider et al. (2016), WISE 1019−3911 was expected to be a T dwarf, with an estimated spectral type based on photometry of T4, an estimated distance of 19–28 pc, and was also a subdwarf candidate. We observed it using CTIO/ARCoIRIS, and spectral typed it as a T3 (blue) with a distance of 25.1 ± 0.32 pc. The other two, WISE 0004−2604 and WISE 0301−2319, were not subdwarf candidates. WISE 0004−2604 was a late-type candidate with an estimated spectral type, based on photometry of T0.5, and WISE 0301−2319 was a nearby late-type candidate with an estimated spectral type, based on photometry, of T0.5, and an estimated distance of 24–33 pc. We observed both of them with IRTF/SpeX, and typed WISE 0004−2604 as T2 (blue) with a distance of 25 ± 2.3 pc and WISE 0301−2319 as T1 (sl. blue) with a distance of 27 ± 2.3 pc.

If confirmed, these three objects would more than double the number of known early-type T subdwarfs. To date, only two early-type T subdwarfs are known: the sdT0 WISE 071121.36−573634.2 discovered by Kellogg et al. (2018) as part of the follow-up for the AllWISE2 motion survey (Kirkpatrick et al. 2016), and the sdT1.5 WISE 210529.08−623558.7 discovered by Luhman & Sheppard (2014) as part of an analysis of high proper motion objects from the WISE survey. In addition, there are three published late-type T subdwarfs: the sdT5.5 HIP 73786B, a common proper motion companion to the metal-poor K-star HIP 73786 discovered by Murray et al. (2011) using data from the United Kingdom InfraRed Telescope Infrared Deep Sky Survey (UKIDSS); the sdT6.5 ULAS J131610.28+075553.0 discovered by Burningham et al. (2014) in the UKIDSS Large Area Survey; and the sdT8 WISE J200520.38+542433.9, a companion to the sdM1.5 Wolf 1130, discovered by Mace et al. (2013) using photometry from 2MASS, WISE, and other telescopes. Although it was not initially designated as a T subdwarf, Burgasser et al. (2006) showed that the peculiar T6 dwarf 2MASS 0937+2931 has a subsolar metallicity and has a spectral morphology consistent with other T subdwarfs. In addition, Zhang et al. (2019) report 38 metal-poor T dwarfs that show suppressed K-band flux in their spectra, which they believe might be T subdwarfs. All of these have spectral types of T5 or later.

As discussed above, there are gaps in our sequence of subdwarf spectral standards. We do have spectra of several subdwarf candidates at these missing spectral types including two candidate sdM4: WISE 1113+5010 and WISE 1710−1801; three new candidate sdL5: WISE 0328+0155, WISE 0413−2023, and WISE 2249−1627; and three new candidate T subdwarfs: WISE 0301−2319 (sdT1), WISE 0004−2604 (sdT2), and WISE 1019−3911 (sdT3). These objects could potentially be used to fill in these holes in the sequence. This is beyond the scope of this work but, in the future these spectra could aid in the construction of a more complete classification scheme for subdwarfs.

We also calculated tangential velocities and their uncertainties for each of our objects, using a Monte Carlo approach to properly account for the uncertainties in the distances and proper motions. Normal distributions were constructed for μ_α, μ_δ, and distance, using their uncertainties. Values for each were randomly drawn from those distributions and used to calculate v_tan. This process was repeated 10,000 times, and the resulting distribution was fit to determine v_tan and its uncertainty for each object. These values are reported in Table 5 and plotted in Figure 9. In Dupuy & Liu (2012), they computed the membership probability as a function of tangential velocity for the thin-disk, thick-disk, and halo populations. Based on the results plotted in Figure 31 of that paper, we define the v_tan values for these regions as follows: halo v_tan ≳ 250 km s⁻¹; thick disk 100 km s⁻¹ ≲ v_tan ≳ 250 km s⁻¹; and thin disk v_tan ≲ 100 km s⁻¹. All three of the extreme subdwarfs in our sample have v_tan ≳ 250 km s⁻¹, putting them in the halo, as expected of older, lower metallicity subdwarfs, which tend to be kinematically associated with the halo population. The dwarfs in our sample are likely clustered in the thin disk, though it is likely some are also in the thick disk. The subdwarfs in our sample are likely distributed throughout the thick and thin disk. Three of our dwarfs have tangential velocities that place them in the halo: WISE 0101+0336 (355.0 ± 30.1 km s⁻¹), WISE 0924+0723 (290 ± 26 km s⁻¹), and WISE 1113+5010 (460 ± 76 km s⁻¹). The velocity of WISE 1113+5010 is approaching the escape velocity of the Galaxy, which is v_tan = ${528}_{-25}^{+24}$ km s⁻¹ at the Sun's position (Deason et al. 2019).

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Table 5.  Photometry, Proper Motions, Spectral Types, and Tangential Velocities of All Observed Objects

AllWISE	2MASS J	2MASS H	2MASS Ks	WISE W1	WISE W2	${\mu }_{\alpha }$	${\mu }_{\delta }$	vtan	Spectral
Designation	(mag)	(mag)	(mag)	(mag)	(mag)	(mas yr−1)	(mas yr−1)	km s−1	Type
J000430.66−260402.3	16.487 ± 0.133	15.587 ± 0.129	>15.523	15.211 ± 0.038	14.127 ± 0.044	11.9 ± 15.3	−229.6 ± 13.8	27 ± 2.9	T2 (blue)
J000458.47−133655.1	16.841 ± 0.171	16.120 ± 0.207	>15.410	15.120 ± 0.037	14.457 ± 0.056	431.3 ± 21.8	−37.4 ± 20.3	59 ± 6.3	T2
J000536.63−263311.8	17.171 ± 0.225	15.849 ± 0.165	15.191 ± 0.154	14.924 ± 0.033	14.261 ± 0.047	384.0 ± 22.8	39.8 ± 20.5	56 ± 5.8	T0 (pec)
J000856.39−281321.7	16.727 ± 0.137	15.664 ± 0.139	15.049 ± 0.131	14.119 ± 0.027	13.636 ± 0.037	284.3 ± 16.0	−54.7 ± 13.6	40 ± 4.0	L8
J010134.83+033616.0	15.418 ± 0.052	14.650 ± 0.066	14.300 ± 0.069	14.206 ± 0.029	13.941 ± 0.039	591.3 ± 10.0	−557.8 ± 8.5	360 ± 30.	M7
J010631.20−231415.1	17.338 ± 0.235	16.115 ± 0.204	15.683 ± 0.241	14.899 ± 0.033	14.417 ± 0.049	−271.5 ± 24.8	−201.6 ± 23.2	57 ± 6.6	L9
J011049.18+192000.1	14.708 ± 0.032	14.142 ± 0.038	13.827 ± 0.05	13.467 ± 0.025	13.147 ± 0.03	451.9 ± 6.0	38.0 ± 6.0	130 ± 10.	M8
J013525.38+020518.2	16.622 ± 0.129	15.481 ± 0.104	15.123 ± 0.117	14.283 ± 0.028	13.883 ± 0.04	102.9 ± 16.2	−494.1 ± 15.2	60 ± 5.4	T0 (sl. red)
J022721.93+235654.3	16.663 ± 0.135	15.647 ± 0.105	15.270 ± 0.155	14.304 ± 0.027	13.690 ± 0.035	310.0 ± 15.2	−139.0 ± 13.6	44 ± 4.2	L9
J030119.39−231921.1	16.635 ± 0.144	15.800 ± 0.158	15.579 ± 0.234	14.829 ± 0.03	14.036 ± 0.036	263.7 ± 27.9	−141.4 ± 22.9	38 ± 4.7	T1 (sl. blue)
J030919.70−501614.2a	⋯	⋯	⋯	16.465 ± 0.057	13.631 ± 0.031	⋯	⋯	⋯	T7
J031627.79+265027.5	16.585 ± 0.149	15.592 ± 0.159	>15.159	14.980 ± 0.035	13.934 ± 0.04	209.0 ± 22.5	−15.6 ± 20.2	22 ± 3.1	T3
J032309.12−590751.0	16.881 ± 0.189b	>16.669	>16.262	16.804 ± 0.065	14.529 ± 0.039	542.9 ± 24.0	476.7 ± 21.4	66 ± 7.6	T7
J032838.73+015517.7	16.504 ± 0.172	>16.598	15.202 ± 0.182	14.645 ± 0.031	14.327 ± 0.053	190.8 ± 22.7	−233.2 ± 19.0	66 ± 7.8	L5 (blue)
J033346.88+385152.6	16.073 ± 0.071	15.276 ± 0.082	15.000 ± 0.118	14.654 ± 0.03	14.350 ± 0.047	240.4 ± 9.7	−324.3 ± 9.8	200 ± 17	M8
J034409.71+013641.5	>17.024	15.949 ± 0.198	15.549 ± 0.232	14.647 ± 0.034	14.183 ± 0.05	−72.0 ± 31.2	−286.6 ± 30.3	51 ± 7.2	L8
J034858.75−562017.8	16.652 ± 0.151	>15.940	>15.517	14.233 ± 0.028	13.919 ± 0.036	169.7 ± 18.0	206.6 ± 16.3	36 ± 4.3	T3
J041353.96−202320.3	16.392 ± 0.111	15.444 ± 0.116	15.132 ± 0.174	14.233 ± 0.028	13.919 ± 0.036	−41.8 ± 15.0	−349.9 ± 14	20 ± 2.7	L5 (blue)
J041743.13+241506.3	15.766 ± 0.069	15.654 ± 0.136	15.450 ± 0.167	14.520 ± 0.032	13.374 ± 0.035	403.6 ± 10.1	−489.8 ± 10.2	35 ± 3.2	T6
J053424.45+165255.0	15.445 ± 0.041	14.385 ± 0.037	13.572 ± 0.041	12.969 ± 0.024	12.575 ± 0.025	−69.0 ± 6.4	−76.4 ± 6.4	16 ± 1.7	L2 (pec)
J054455.54+063940.3	14.039 ± 0.032	13.286 ± 0.028	12.795 ± 0.033	12.494 ± 0.024	12.265 ± 0.025	157.7 ± 12.8	−329.2 ± 11.9	61 ± 5.3	M9
J061429.77+383337.5	13.523 ± 0.024	12.748 ± 0.029	12.251 ± 0.02	11.848 ± 0.024	11.619 ± 0.022	84.9 ± 6.9	−385.8 ± 6.8	50 ± 4.2	M9
J062858.69+345249.2	15.957 ± 0.084	15.265 ± 0.089	14.706 ± 0.084	13.923 ± 0.027	13.615 ± 0.039	8.2 ± 7.4	−286.5 ± 7.4	54 ± 4.7	L4
J063552.52+514820.4	>16.680	15.504 ± 0.144	15.416 ± 0.180	14.610 ± 0.031	14.294 ± 0.046	−121.1 ± 18.9	−243.2 ± 17.3	37 ± 4.2	T0
J084254.56−061023.7	16.040 ± 0.076	15.680 ± 0.111	>15.127	15.444 ± 0.041	14.086 ± 0.041	−375.9 ± 14.9	−45.0 ± 14.4	37 ± 3.7	T4
J085039.11−022154.3	15.443 ± 0.044	14.504 ± 0.041	14.100 ± 0.059	13.408 ± 0.025	13.100 ± 0.028	−392.0 ± 6.7	−132.1 ± 6.7	47 ± 6.6	sdL7 (red)
J085633.87−181546.6	15.828 ± 0.071	15.252 ± 0.094	14.473 ± 0.095	14.350 ± 0.029	14.178 ± 0.043	76.7 ± 8.3	−251.5 ± 7.7	80 ± 7.0	L1
J092453.76+072306.0	15.752 ± 0.083	15.272 ± 0.094	14.754 ± 0.112	14.722 ± 0.032	14.488 ± 0.054	−248.4 ± 11.1	−383.2 ± 10.7	290 ± 27	M6
J094812.21−290329.5	15.542 ± 0.056	15.019 ± 0.066	14.848 ± 0.122	14.332 ± 0.028	13.962 ± 0.03	−370.3 ± 7.8	−238.0 ± 8.0	150 ± 20	sdL1
J095230.79−282842.2	14.942 ± 0.043	14.451 ± 0.041	14.050 ± 0.058	13.934 ± 0.027	13.651 ± 0.034	−572.2 ± 7.2	276.3 ± 7.2	340 ± 46	esdM4
J101944.62−391151.6	16.027 ± 0.096	15.766 ± 0.125	15.727 ± 0.267	15.645 ± 0.044	14.217 ± 0.042	−472.2 ± 28.0	222.7 ± 26.4	58 ± 5.9	T3 (blue)
J103534.63−071148.2	16.393 ± 0.094	15.843 ± 0.128	15.145 ± 0.141	14.381 ± 0.029	14.085 ± 0.045	−375.5 ± 18.9	−28.4 ± 15.8	80 ± 11.	sdL7
J111320.39+501010.5	15.506 ± 0.06	14.804 ± 0.086	14.898 ± 0.113	14.603 ± 0.029	14.411 ± 0.046	−167.3 ± 10.8	−313.2 ± 10.9	330 ± 54	M4 (blue)
J112158.76+004412.3	15.961 ± 0.077	15.256 ± 0.075	14.877 ± 0.133	14.715 ± 0.033	14.297 ± 0.047	−383.0 ± 9.5	−133.0 ± 9.8	224 ± 20	M7 (blue)
J112859.45+511016.8	16.189 ± 0.069	15.110 ± 0.078	14.490 ± 0.069	13.944 ± 0.026	13.692 ± 0.032	−117.7 ± 9.0	−321.9 ± 9.1	74 ± 6.4	L3
J120751.17+302808.9	15.253 ± 0.051	14.799 ± 0.071	14.467 ± 0.077	14.046 ± 0.027	13.713 ± 0.033	126.1 ± 9.1	−241.1 ± 7.2	100 ± 8.9	M8
J121231.97−050750.7	14.676 ± 0.032	14.201 ± 0.028	13.845 ± 0.049	13.663 ± 0.028	13.366 ± 0.033	−474.2 ± 7.0	−21.9 ± 7.1	160 ± 13	M7 (sl. blue)
J121914.75+081027.0	15.780 ± 0.085	15.076 ± 0.096	14.979 ± 0.148	14.796 ± 0.034	14.567 ± 0.059	−279.9 ± 11.4	−347.7 ± 11.1	250 ± 34	sdM7
J122042.20+620528.3	15.433 ± 0.054	14.830 ± 0.062	14.730 ± 0.086	14.487 ± 0.029	14.152 ± 0.034	−467.9 ± 9.4	−280.9 ± 8.7	230 ± 19	sdM7
J123513.87−045146.5	15.681 ± 0.072	15.195 ± 0.083	15.029 ± 0.142	14.808 ± 0.033	14.535 ± 0.057	−230.0 ± 10.1	−351.4 ± 9.9	317 ± 44	esdM4
J124516.66+601607.5	15.663 ± 0.058	15.297 ± 0.104	15.086 ± 0.116	14.711 ± 0.028	14.502 ± 0.043	−294.7 ± 11.1	−239.8 ± 9.7	190 ± 26	sdM8.5
J133520.09−070849.3	16.336 ± 0.097	15.365 ± 0.09	14.989 ± 0.134	14.932 ± 0.034	14.565 ± 0.056	−367.5 ± 11.9	84.1 ± 12.0	230 ± 21	M7
J134359.71+634213.1	16.004 ± 0.085	15.202 ± 0.106	14.795 ± 0.096	14.476 ± 0.025	14.262 ± 0.033	−254.0 ± 12.4	86.7 ± 8.3	130 ± 12	M8
J143942.79−110045.4	15.837 ± 0.086	15.365 ± 0.098	15.038 ± 0.145	14.586 ± 0.03	14.213 ± 0.043	−252.3 ± 9.8	−207.6 ± 9.3	130 ± 18	sdL1
J144056.64−222517.8	15.077 ± 0.05	14.688 ± 0.058	14.453 ± 0.087	14.108 ± 0.029	13.780 ± 0.042	−239.5 ± 7.8	−247.3 ± 7.9	130 ± 18	sdM8.5
J145645.54−103343.5	14.856 ± 0.049	14.197 ± 0.055	13.849 ± 0.044	13.467 ± 0.026	13.166 ± 0.031	29.2 ± 7.1	−302.3 ± 7.1	87 ± 7.6	M8 (sl. blue)
J145747.55−094719.3	15.331 ± 0.048	14.930 ± 0.063	14.688 ± 0.097	14.377 ± 0.029	14.205 ± 0.048	−313.9 ± 8.6	−250.9 ± 8.0	260 ± 36	esdM4
J155225.22+095155.5	15.923 ± 0.088	15.360 ± 0.082	15.164 ± 0.147	14.756 ± 0.03	14.554 ± 0.054	−241.5 ± 12.1	−291.8 ± 11.5	230 ± 33	sdM7
J165057.66−221616.8	12.218 ± 0.024	11.679 ± 0.027	11.332 ± 0.026	11.122 ± 0.023	10.929 ± 0.021	−123.3 ± 5.9	−266.1 ± 5.9	57 ± 8.9	M5
J171059.52−180108.7	12.314 ± 0.027	11.800 ± 0.025	>11.509	11.208 ± 0.024	11.027 ± 0.021	−84.8 ± 7.5	−365.1 ± 7.3	110 ± 22	M4(blue)
J171105.08−275531.7	12.760 ± 0.033	12.190 ± 0.036	11.853 ± 0.037	11.456 ± 0.024	11.315 ± 0.023	−169.0 ± 6.2	−373.0 ± 6.1	63 ± 5.6	M6
J171454.88+064349.8	16.617 ± 0.132	15.467 ± 0.114	14.594 ± 0.089	14.066 ± 0.026	13.782 ± 0.036	−83.2 ± 10.6	−322.0 ± 10.6	88 ± 8.0	L2 (red)
J173551.56−820900.3	16.393 ± 0.14	>15.949	>15.996	15.570 ± 0.036	13.723 ± 0.029	−232.3 ± 16.3	−253.4 ± 15.5	21 ± 2.4	T7
J180839.55+070021.7	16.125 ± 0.104	15.731 ± 0.143	15.338 ± 0.169	14.821 ± 0.034	14.497 ± 0.055	−235.1 ± 21.4	−177.8 ± 19.8	110 ± 12	L1 (blue)
J182010.20+202125.8	15.188 ± 0.051	14.802 ± 0.071	14.606 ± 0.076	14.409 ± 0.03	14.174 ± 0.04	−341.1 ± 8.5	−45.4 ± 8.5	130 ± 19	sdM8.5
J183654.10−135926.2	12.997 ± 0.024	12.433 ± 0.023	12.031 ± 0.019	11.542 ± 0.028	11.480 ± 0.029	−21.2 ± 6.5	−368.2 ± 6.6	61 ± 5.3	M6
J191011.03+563429.3	13.281 ± 0.027	12.654 ± 0.033	12.231 ± 0.026	11.825 ± 0.022	11.549 ± 0.021	−364.6 ± 7.8	335.7 ± 6.9	68 ± 5.7	M8
J201252.78+124633.3	12.040 ± 0.021	11.425 ± 0.021	11.035 ± 0.018	10.796 ± 0.023	10.596 ± 0.02	282.7 ± 6.0	151.7 ± 5.9	30 ± 2.6	M7 (sl. red)
J211157.84−521111.3	16.563 ± 0.166	15.923 ± 0.212	>15.252	15.371 ± 0.039	14.308 ± 0.043	−227.2 ± 28.5	87.3 ± 26.7	30 ± 4.4	T3
J215550.34−195428.4	>16.978	15.971 ± 0.146	15.277 ± 0.142	14.552 ± 0.03	14.172 ± 0.044	−34.0 ± 16.8	−352.7 ± 16.1	66 ± 6.7	L7
J221737.41−355242.7	14.874 ± 0.051	14.540 ± 0.068	14.236 ± 0.066	13.816 ± 0.025	13.573 ± 0.032	49.0 ± 7.1	−304.9 ± 7.1	220 ± 35	M5
J223444.44−230916.1	15.262 ± 0.086	14.831 ± 0.11	14.082 ± 0.027	13.745 ± 0.037	16.121 ± 0.085	408.9 ± 24.8	−26.8 ± 22.5	110 ± 12	L5
J224931.10−162759.6	17.328 ± 0.228	16.284 ± 0.24	>14.679	14.843 ± 0.034	14.368 ± 0.053	374.5 ± 8.8	126.2 ± 8.7	69 ± 6.0	L7
J230743.63+052037.3	14.741 ± 0.038	14.058 ± 0.027	13.763 ± 0.039	13.159 ± 0.024	13.032 ± 0.028	−133.3 ± 8.5	−107.5 ± 7.7	52 ± 5.0	M7
J234404.85−250042.2	15.253 ± 0.056	14.634 ± 0.079	14.392 ± 0.083	13.881 ± 0.027	13.563 ± 0.034	342.7 ± 7.5	−167.6 ± 6.8	150 ± 13	M7

Notes.

^aWISE 030919.70−501614.2 does not show up in 2MASS, and therefore does not have a 2MASS–AllWISE proper motion, and also does not have a calculated v_tan. ^bThe 2MASS J-band photometry for WISE 032309.12−590751.0 was taken from the 2MASS reject table.

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