J/AJ/156/76 New young stars and brown dwarfs in Upper Sco (Luhman+, 2018)
New young stars and brown dwarfs in the Upper Scorpius association.
Luhman K.L., Herrmann K.A., Mamajek E.E., Esplin T.L., Pecaut M.J.
<Astron. J., 156, 76 (2018)>
=2018AJ....156...76L 2018AJ....156...76L (SIMBAD/NED BibCode)
ADC_Keywords: Associations, stellar ; Stars, pre-main sequence ;
Stars, brown dwarf ; Spectral types ; Extinction ;
Photometry, infrared ; Equivalent widths ; Spectroscopy
Keywords: brown dwarfs - stars: formation - stars: low-mass -
stars: luminosity function, mass function - stars: pre-main sequence
Abstract:
To improve the census of the Upper Sco association (∼11 Myr, ∼145 pc),
we have identified candidate members using parallaxes, proper motions,
and color-magnitude diagrams from several wide-field imaging surveys
and have obtained optical and infrared spectra of several hundred
candidates to measure their spectral types and assess their membership.
We also have performed spectroscopy on a smaller sample of previously
known or suspected members to refine their spectral types and evidence
of membership. We have classified 530 targets as members of Upper Sco,
377 of which lack previous spectroscopy. Our new compilation of all
known members of the association contains 1631 objects. Although the
census of Upper Sco has expanded significantly over the last decade,
there remain hundreds of candidates that lack spectroscopy. The
precise parallaxes and proper motions from the second data release of
Gaia should extend down to substellar masses in Upper Sco, which will
greatly facilitate the identification of the undiscovered members.
Description:
During a study of circumstellar disks in Upper Sco, Luhman & Mamajek
(2012, J/ApJ/758/31) compiled a list of known members of the association.
That list contained 863 sources, 181 of which comprised an initial sample
of new members found through the survey that we are presenting in this
work. Many additional members have been identified by subsequent surveys
of Upper Sco. We have revised and expanded the compilation of members
from Luhman & Mamajek (2012, J/ApJ/758/31) to account for those surveys
and new membership constraints.
We have obtained optical and near-IR spectra of candidate members of
Upper Sco from the previous section to measure their spectral types and
assess their membership. We also have observed a sample of stars that
were previously known or suspected to be members to improve their spectral
classifications and evidence of membership. These data were taken between
2009 and 2017 at the 1.5 m SMARTS and 4 m Blanco telescopes at the Cerro
Tololo Inter-American Observatory (CTIO), the NASA Infrared Telescope
Facility (IRTF), the Southern Astrophysical Research Telescope (SOAR),
and the Gemini North and South telescopes.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 207 1631 Members of Upper Sco
table2.dat 174 1196 Candidate members of Upper Sco
table4.dat 108 769 Spectroscopic data for previously known and
candidate members of Upper Sco
refs.dat 122 84 List of references
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See also:
III/80 : Michigan Catalogue of HD stars, Vol.3 (Houk, 1982)
III/133 : Michigan Catalogue of HD stars, Vol.4 (Houk+, 1988)
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
I/311 : WISE All-Sky Data Release (Cutri+ 2012)
II/328 : AllWISE Data Release (Cutri+ 2013)
I/337 : Gaia DR1 (Gaia Collaboration, 2016)
J/ApJS/101/117 : UBVRIJHKLMNQ photometry in Taurus-Auriga (Kenyon+ 1995)
J/AJ/120/479 : Low-mass stars in the Upper Sco association (Ardila+, 2000)
J/AJ/131/3016 : Low-mass objects in Upper Scorpius (Slesnick+, 2006)
J/MNRAS/374/372 : ZYJHK photometry in Upper Sco (Lodieu+, 2007)
J/ApJ/688/377 : Low-mass objects in Upper Scorpius. II. (Slesnick+, 2008)
J/ApJS/186/111 : Spitzer observations of Taurus members (Luhman+, 2010)
J/A+A/527/A24 : Spectra of low-mass stars in Upper Sco (Lodieu+, 2011)
J/MNRAS/418/1231 : New brown dwarfs in upper Sco (Dawson+, 2011)
J/ApJ/758/31 : IR photometry for members of Upper Sco (Luhman+, 2012)
J/MNRAS/429/903 : New brown dwarf discs in Upper Scorpius (Dawson+, 2013)
J/AJ/153/46 : Spectroscopy of candidate members in Taurus (Luhman+, 2017)
J/AJ/154/256 : VLM stars and BDs in Upper Sco using Gaia DR1 (Cook+, 2017)
J/AJ/156/71 : K2 Campaign 2: young disk-bearing stars in Sco + Oph
(Cody+, 2018)
J/AJ/156/75 : Circumstellar disks in the Upper Sco association
(Esplin+, 2018)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 18 A18 --- 2MASS 2MASS Point Source Catalog (Cat. II/246) source
name
20- 39 A20 --- WISEA AllWISE Source Catalog (Cat. II/328) source name
(1)
41- 59 A19 --- UGCS UKIDSS Galactic Clusters Survey source name (G1)
61-130 A70 --- OName Other source name(s)
132-141 F10.6 deg RAdeg Right Ascension in decimal degrees (J2000)
143-152 F10.6 deg DEdeg Declination in decimal degrees (J2000)
154-176 A23 --- SpType ? Spectral type(s)
178-191 A14 --- r_SpType ? Spectral type reference(s) (see refs.dat file)
193-197 A5 --- ASpType ? Adopted spectral type
199-202 F4.2 mag Ak [0/1.47]? Extinction in Ks
204-207 A4 --- f_Ak ? Method of extinction estimation (2)
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Note (1): The following names are from the WISE All-Sky Source Catalog
(Cat. II/311): J160027.15-223850.5, J160414.16-212915.5, J161320.78-175752.3,
J161317.38-292220.0, J161837.22-240522.8, J162210.14-240905.4,
J162230.38-241119.2, J162620.15-223312.8.
Note (2): Extinction estimated from a near-IR spectrum (spec) or the indicated
color (e.g., J-H) assuming the intrinsic spectrum from Luhman et al. (2017,
J/AJ/153/46) or the intrinsic color from Kenyon & Hartmann (1995,
J/ApJS/101/117) and Luhman et al. (2010, J/ApJS/186/111) for the spectral type
in question.
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Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 17 A17 --- 2MASS 2MASS Point Source Catalog (Cat. II/246) source
name
19- 37 A19 --- WISEA AllWISE Source Catalog (Cat. II/328) source name
39- 57 A19 --- UGCS UKIDSS Galactic Clusters Survey source name (G1)
59- 68 F10.6 deg RAdeg Right Ascension in decimal degrees (J2000)
70- 79 F10.6 deg DEdeg Declination in decimal degrees (J2000)
81- 89 A9 --- SpType ? Spectral type(s)
91- 93 A3 --- f_SpType ? Spectral type reference(s) (1)
95- 99 F5.2 mag Jmag [7.64/19.31]? J magnitude
101-104 F4.2 mag e_Jmag [0.02/0.14]? Error in Jmag
106-110 F5.2 mag Hmag [7.04/18.5] H magnitude
112-115 F4.2 mag e_Hmag [0.02/0.15] Error in Hmag
117-121 F5.2 mag Ksmag [6.84/17.47] Ks magnitude
123-126 F4.2 mag e_Ksmag [0.01/0.1] Error in Ksmag
128 A1 --- f_Jmag Reference for Jmag (2)
129 A1 --- f_Hmag Reference for Hmag (2)
130 A1 --- f_Ksmag Reference for Ksmag (2)
132-174 A43 --- Selec Selection criteria satisfied by candidate (3)
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Note (1): Spectral type reference as follows:
1 = Esplin et al. (2018AJ....156...75E 2018AJ....156...75E);
2 = This work;
3 = Houk & Smith-Moore (1988, Cat. III/133);
4 = Slesnick et al. (2008ApJ...688..377S 2008ApJ...688..377S);
5 = Houk (1982, Cat. III/80);
6 = Rizzuto et al. (2015MNRAS.448.2737R 2015MNRAS.448.2737R);
7 = Cieza et al. (2007ApJ...667..308C 2007ApJ...667..308C).
Note (2): JHKs reference as follows:
2 = 2MASS Point Source Catalog (Cat. II/246);
u = UKIDSS Data Release 10;
v = VISTA VHS Data Release 5.
Note (3): Selection criteria satisfied by candidate are defined as follows:
G/W/i/Y/Z/ip/zp/yp = CMDs in Figure 4 (all candidates also satisfy the H-Ks
diagram in Figure 5);
pi = Parallax from Gaia DR1 (Cat. I/337);
gaia/gps/ucac/2m-gaia/2m-ps/ukidss = Proper motions in Figure 3.
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Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 24 A24 --- Name Source name (1)
26- 35 F10.6 deg RAdeg Right Ascension in decimal degrees (J2000)
37- 46 F10.6 deg DEdeg Declination in decimal degrees (J2000)
48- 58 A11 --- SpType Spectral type(s) (2)
60 A1 --- l_EW(Li) [<] Limit flag on EW(Li)
61- 64 F4.2 0.1nm EW(Li) [0.05/1.1]? Equivalent Width of Li
66- 68 F3.1 0.1nm EW(Na) [1.5/5.7]? Equivalent Width of Na
70- 81 A12 --- Inst Instrument(s)
83-105 A23 --- Date Date(s)
107-108 A2 --- Mem Membership flag (3)
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Note (1): Source names are from the 2MASS Point Source Catalog (Cat. II/246)
when available. Otherwise, they are from the UKIDSS Galactic Clusters Survey.
Note (2): Uncertainties are 0.25 and 0.5 subclass for optical and IR spectral
types, respectively, unless indicated otherwise.
Note (3): Stars with membership flags of either "Y" or "Y?" are included in our
compilation of adopted members of Upper Sco in Table 1. Among the 530
spectroscopic targets that are adopted as members, 377 have not been
previously observed with spectroscopy. Stars that have undetermined membership
(marked as "?") and that satisfy our latest set of selection criteria from the
CMDs and proper motions are included in the sample of candidate members in
Table 2.
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Byte-by-byte Description of file: refs.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 I2 --- Ref Reference code
4- 66 A63 --- Aut Author's name(s)
68- 86 A19 --- Bibcode Bibcode of the reference
88-122 A35 --- Com Comment
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Global notes:
Note (G1): Based on coordinates from Data Release 10 of the UKIDSS Galactic
Clusters Survey for stars with Ks>10 from 2MASS.
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History:
11-Mar-2019: From electronic version of the journal
10-Aug-2020: in table4, UGCS J160918.67-222923.8 corrected into
UGCS J161248.97-180049.5
(End) Prepared by [AAS], Tiphaine Pouvreau [CDS] 06-Feb-2019