Quick search Find article
Quick search
Find article

A NEW X-RAY ANALYSIS OF THE OPEN CLUSTER BLANCO 1 USING WIDE-FIELD BVIc PHOTOMETRIC* AND PROPER MOTION SURVEYS

FREE ISSUE

P. A. Cargile1, D. J. James1,2 and I. Platais3

Show affiliations


We perform a new analysis of the extant ROSAT and XMM-Newton X-ray surveys of the southern open cluster Blanco 1, utilizing new BVIc photometric and proper motion data sets. In our study, we match optical counterparts to 47 X-ray sources associated with Blanco 1 cluster members, six of which were listed in previous X-ray studies as cluster nonmembers. Our new catalog of optical counterparts to X-ray sources clearly traces out the Blanco 1 main sequence in a color-magnitude diagram, extending from early G to mid-M spectral types. Additionally, we derive new X-ray luminosities as well as ratios of X-ray to bolometric luminosities for confirmed cluster members. We compare these X-ray properties to other young open clusters, including the coeval Pleiades cluster, to investigate the relationship between age and X-ray activity. We find that stars in Blanco 1 generally exhibit X-ray properties similar to those of other open clusters, namely increasing Lx /L bol with reducing mass for earlier-type stars, and a saturation limit of Lx /L bol at a magnitude of 10–3 for stars with VIc gsim 1.25. More generally, the X-ray detected stars in Blanco 1 have X-ray emission magnitudes that agree with the overall trends seen in the other young clusters. We observe that X-ray emission decays as a function of age and the rate of this decay is mass dependent. Specifically, for higher mass stars, the trend is Skumanich like (i.e., Lx /L bol vprop age–1/2); however, as one goes to lower masses the magnitude of X-ray emission becomes less of a function of age. In fact, for the lowest mass stars (M-type), there is no observable reduction in X-ray production during the first ~1 Gyr of their lives. However, due to a lack of sensitivity to low X-ray fluxes, there may exist M-type stars that have less than saturated levels of X-ray flux which are not included in our study. In a direct comparison of Blanco 1 to the Pleiades open cluster, members of both clusters have similar X-ray characteristics; however, there does appear to be some discrepancies in the distribution of Lx /L bol as a function of color that may be related to scatter seen in the Pleiades CMD. Moreover, previous comparisons of this nature for Blanco 1 were not possible due to the reliance on photographic photometry. This is where the power of precise, homogeneous, and standardized CCD photometry allows for a high fidelity, detailed study of the X-ray properties of stars in Blanco 1, as well as a thorough comparison of Blanco 1 to other well-studied open clusters.


Footnote
*  Based on observations made with the Small- and Medium-Aperture Research Telescope System (SMARTS) at the Cerro Tololo Inter-American Observatory.
Keywords

open clusters and associations: general; open clusters and associations: individual (Blanco 1); stars: activity; stars: evolution; X-rays: stars


Dates

Issue 2 (2009 February)

Received 2008 July 9, accepted for publication 2008 November 13

Published 2009 January 28



  1. A New X-Ray Analysis of the Open Cluster Blanco 1 Using Wide-Field BVIc Photometric and Proper Motion Surveys

    P. A. Cargile et al. 2009 The Astronomical Journal 137 3230

  2. Description of nuclear structure effects in sub-barrier fusion by the interacting boson model

    A B Balantekin and S Kuyucak 1997 J. Phys. G: Nucl. Part. Phys. 23 1159

  3. Proposal for a conformal field theory interpretation of Watts' differential equation for percolation

    Michael Flohr and Annekathrin Müller-Lohmann J. Stat. Mech. (2005) P12004

  4. Status of the LIGO-AURIGA Joint Burst Analysis

    S Poggi et al 2006 J. Phys.: Conf. Ser. 32 198

  5. On uniqueness of charged Kerr–AdS black holes in five dimensions

    Owen Madden and Simon F Ross 2005 Class. Quantum Grav. 22 515

  6. A one-dimensional approach to Gruneisen's constant

    M A Black 1972 Phys. Educ. 7 515

Users also read

What's this?
This innovative new feature generates a list of articles 'also read' by other users based on them reading the original article. Article abstracts citations and references are all considered and weighted accordingly. We hope that this will help you find relevant papers for your research.

  1. Employing a New, BVIc Photometric Survey of IC 4665 to Investigate the Age of This Young Open Cluster
  2. Identification of the Lithium Depletion Boundary and Age of the Southern Open Cluster Blanco 1

View by subject




Export








Please login to access our web services, or create an account if you don't yet have one.

You must have cookies enabled in your web browser to be able to login.

Username
Password

Forgotten your password? Get a new one here.