Data Model: table_A1

General Description
This table lists the optical/infrared parameters of common proper-motion companions to UCDs and UCD candidates that have a proper-motion corrected position
at the mean eRASS1 observing date within 3× the positional at error of an eRASS1 source.
Naming Convention
This file corresponds to Table A.1 in the eROPub138 splash paper: A first eROSITA view of ultracool dwarfs (Stelzer+ 2021).
Filename: table_A1.fits
Approximate Size
16 KB
File Type
FITS
Generated by Product
eSASS (software used to generate the date product, add links)

Sections

Content of the page.

HDU0: PRIMARY

[Write text to summarize contents of this HDU]

HDU Type
IMAGE
HDU Size
3 KB
Header Table Caption for HDU0
KeyValueTypeComment

HDU1: Joined

Data for the 14 common proper-motion pairs.

HDU Type
BINARY TABLE
HDU Size
1 KB
Header Table Caption for HDU1
KeyValueTypeComment
Binary Table Caption for HDU1
NameTypeUnitDescription
source_id_ucd int64 None Gaia DR2 designation of the UCD
source_id int64 None Gaia DR2 designation of the alternative counterpart
other_name char[16] None Main SIMBAD designation of the alternative counterpart
rho float64 arcsec Separation between the UCD and its companion
Gmag float32 mag G-band magnitude from the Gaia DR2 catalog
Jmag float64 mag J-band magnitude from the 2MASS All-Sky PSC catalog
W1mag float64 mag W1-band magnitude from the AllWISE catalog
spt char[8] None Spectral type of the alternative counterpart derived from the G-J color index [note1]
flux_12_CF float64 erg/cm2/s X-ray flux in the eROSITA band 1+2 [note2]
flux_12_err_CF float64 erg/cm2/s Error on the X-ray flux in the eROSITA band 1+2
flag_young bool None Flag for young stars
ref_young char[3] None References indicating young stars
flag_binary bool None Flag for binaries
ref_binary char[8] None References indicating binaries

[note1] We make use of the "Stellar Color/Teff Table" maintained by E. Mamajek.
[note2] We estimated the X-ray flux in the eROSITA band 1+2 from the count rates in the eRASS1 catalog. We estimated the rate-to-flux conversion
factor for this energy band at 7.37 10-13 erg/cts/cm2 by following a procedure similar to that of Magaudda et al. (this volume).

References for the object type

[1] Mason et al. 2001. The 2001 US Naval Observatory Double Star CD-ROM. I. The Washington Double Star Catalog (Vizier catalog: B/wds)

[2] Cruz et al. 2007. Meeting the Cool Neighbors. IX. The Luminosity Function of M7-L8 Ultracool Dwarfs in the Field (Vizier catalog: J/AJ/133/439)

[3] Shkolnik et al. 2009. Identifying the Young Low-mass Stars within 25 pc. I. Spectroscopic Observations (Vizier catalog: J/ApJ/699/649)

[4] Shkolnik et al. 2012. Identifying the Young Low-mass Stars within 25 pc. II. Distances, Kinematics, and Group Membership (Vizier catalog: J/ApJ/758/56)

[5] Zari et al. 2017. Mapping young stellar populations toward Orion with Gaia DR1 (Vizier catalog: J/A+A/608/A148)

[6] Goldman et al. 2018. A Large Moving Group within the Lower Centaurus Crux Association (Vizier catalog: J/ApJ/868/32)

[7] Zari et al. 2018. 3D mapping of young stars in the solar neighbourhood with Gaia DR2 (Vizier catalog: J/A+A/620/A172)

[8] Damiani et al. 2019. Stellar population of Sco OB2 revealed by Gaia DR2 data (Vizier catalog: J/A+A/623/A112)

[9] Kervella et al. 2019. Stellar and substellar companions of nearby stars from Gaia DR2. Binarity from proper motion anomaly (Vizier catalog: J/A+A/623/A72)

[10] Hartman & Lépine. 2020. The SUPERWIDE Catalog: A Catalog of 99,203 Wide Binaries Found in Gaia and Supplemented by the SUPERBLINK High Proper Motion Catalog (Vizier catalog: J/ApJS/247/66)

[11] Sapozhnikov et al. 2020. Binary Star Population with Common Proper Motion in Gaia DR2 (Vizier catalog: J/AZh/97/733)

[12] Tian et al. 2020. The Separation Distribution of Ultrawide Binaries across Galactic Populations (Vizier catalog: J/ApJS/246/4)

References

Skrutskie et al. 2006. The Two Micron All Sky Survey (2MASS) (Vizier catalog: II/246)

Wright et al. 2010. The Wide-field Infrared Survey Explorer (WISE): Mission Description and Initial On-orbit Performance (Vizier catalog: II/328)

Gaia Collaboration, Brown et al. 2018. Gaia Data Release 2. Summary of the contents and survey properties (Vizier catalog: I/345)

Predehl et al. 2020. The eROSITA X-ray telescope on SRG

Acknowledgement

The eROSITA data model structure for catalogues was branched from the SDSS data model for value added catalogues.