J/ApJ/838/150 The Taurus-Auriga ecosystem. I. (Kraus+, 2017)
The greater Taurus-Auriga ecosystem.
I. There is a distributed older population.
Kraus A.L., Herczeg G.J., Rizzuto A.C., Mann A.W., Slesnick C.L.,
Carpenter J.M., Hillenbrand L.A., Mamajek E.E.
<Astrophys. J., 838, 150-150 (2017)>
=2017ApJ...838..150K 2017ApJ...838..150K (SIMBAD/NED BibCode)
ADC_Keywords: Spectral types ; Equivalent widths ; Radial velocities ;
Rotational velocities ; Molecular clouds ; Extinction
Keywords: open clusters and associations: individual (Taurus-Auriga);
stars: formation; stars: pre-main sequence; stars: protostars
Abstract:
The census of Taurus-Auriga has been assembled over seven decades and
inherited the biases and incompleteness of the input studies. The
unusual shape of its inferred initial mass function (IMF) and the
existence of isolated disk-bearing stars suggest that additional
(likely disk-free) members remain to be discovered. We therefore have
begun a global reassessment of the census of Taurus-Auriga that
exploits new data and better definitions of youth and kinematic
membership. As a first step, we reconsider the membership of all
disk-free candidate members from the literature with spectral type
≥F0, 3h50min<α5h40min, and 14°<δ<34°. We combine
data from the literature with Keck/HIRES and UH88/SNIFS spectra to
test the membership of these candidates using the positions in the
Hertzsprung-Russel diagram, proper motions, radial velocities,
Hα, lithium, and surface gravity. We find 218 confirmed or
likely Taurus members, 160 confirmed or likely interlopers, and only
18 that lack sufficient evidence to draw firm conclusions. A
significant fraction of these stars (81/218=37%) are not included in
the most recent canonical member lists. There are few additional
members to the immediate vicinity of the molecular clouds, preserving
the IMFs that have been deemed anomalous in past work. Many of the
likely Taurus members are instead distributed broadly across the
search area. When combined with the known disk hosts, our updated
census reveals two regimes: a high-density population with a high disk
fraction (indicative of youth) that broadly traces the molecular
clouds, and a low-density population with low disk fraction (hence
likely older) that most likely represents previous generations of star
formation.
Description:
High-resolution spectroscopic observations for 35 candidates from the
surveys of Slesnick+ (2006, J/AJ/132/2665) and
Li & Hu (1998, J/A+AS/132/173) were previously obtained with
Keck/HIRES on 2006 December 12 and 13 (PIs Carpenter and Slesnick).
We downloaded these observations, extracted the spectra, and analyzed
them to measure the radial velocity, Hα equivalent width, and Li
equivalent width for each object.
We observed 32 candidates with the SuperNova Integral Field
Spectrograph (SNIFS) on the University of Hawaii 2.2m telescope
between 2014 November and 2015 January (PIs Herczeg and Mann). These
observations (R∼1000) are similar to those described by
Mann+ (2015, J/ApJ/804/64), who describe some of the observations and
reductions in more detail.
See section 3 for further details.
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 106 396 Candidate class III members of Taurus-Auriga
table2.dat 61 285 Literature Hα measurements for
candidate class III Taurus members
table3.dat 48 159 Literature lithium measurements for
candidate class III Taurus members
table4.dat 51 129 Literature radial velocity measurements for
candidate class III Taurus members
table5.dat 91 35 Keck/HIRES observations of candidate Taurus members
table6.dat 68 32 UH88/SNIFS observations of candidate Taurus members
table7.dat 42 43 Na8189 indices for candidate class III Taurus
members of Herczeg & Hillenbrand
(2014, J/ApJ/786/97)
table8.dat 62 396 Membership diagnostics
refs.dat 90 122 References
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See also:
I/282 : The CMT CCD Drift Scan Survey (Evans+, 2002)
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
V/117 : Geneva-Copenhagen Survey of Solar neighbourhood (Holmberg+, 2007)
V/139 : The SDSS Photometric Catalog, Release 9 (Adelman-McCarthy+, 2012)
I/329 : URAT1 Catalog (Zacharias+ 2015)
J/ApJS/101/117 : UBVRIJHKLMNQ photometry in Taurus-Auriga (Kenyon+ 1995)
J/A+A/297/391 : T Tauri stars ROSAT survey (Neuhaeuser+, 1995)
J/A+A/312/439 : New T Tauri stars in Taurus-Auriga (Wichmann+, 1996)
J/A+AS/132/173 : New weak-line T Tauri stars in Taurus-Auriga (Li+ 1998)
J/AJ/129/2294 : RVs of weak-lines T Tauri stars (Massarotti+, 2005)
J/A+A/446/485 : New very low-mass members in Taurus (Guieu+, 2006)
J/ApJ/645/676 : Spatial distribution of brown dwarfs in Taurus (Luhman+, 2006)
J/ApJ/647/1180 : Infrared photometry of Taurus SFR (Luhman+, 2006)
J/AJ/132/2665 : QUEST2 BRI photometry of Taurus-Auriga PMS (Slesnick+, 2006)
J/A+A/468/353 : XMM-Newton Extended Survey of Taurus (Guedel+, 2007)
J/AJ/133/2524 : Spectra of young nearby stars (White+, 2007)
J/ApJ/696/L84 : Primordial circumstellar disks in binary syst. (Cieza+, 2009)
J/ApJS/181/321 : Properties of Spitzer c2d dark clouds (Evans+, 2009)
J/ApJ/704/531 : The coevality of young binary systems (Kraus+, 2009)
J/ApJ/699/649 : Young M dwarfs within 25pc. I. (Shkolnik+, 2009)
J/ApJ/709/L114 : Protoplanetary disks in PMS binaries (Duchene, 2010)
J/AJ/139/1338 : UV-selected stars in Tau and Upper Sco (Findeisen+, 2010)
J/ApJS/186/111 : Spitzer observations of Taurus members (Luhman+, 2010)
J/ApJS/186/259 : Taurus Spitzer survey: new candidate members (Rebull+, 2010)
J/ApJ/723/1542 : Optical high-resolution spectroscopy of WTTSs (Xing, 2010)
J/ApJ/731/8 : Multiple star formation in Taurus-Auriga (Kraus+, 2011)
J/ApJS/196/4 : New young star candidates in Taurus-Auriga (Rebull+, 2011)
J/ApJ/757/141 : Companion IR det. limits in young associations (Kraus+, 2012)
J/ApJ/745/19 : Binary systems in Taurus-Auriga (Kraus+, 2012)
J/ApJ/745/119 : Close companions to young stars. I. ChaI & Tau (Nguyen+, 2012)
J/ApJ/758/56 : Young M dwarfs within 25pc. II. Kinematics (Shkolnik+, 2012)
J/ApJ/771/110 : Early-type stars in Taurus-Auriga (Mooley+, 2013)
J/ApJS/208/9 : Intrinsic colors and temperatures of PMS stars (Pecaut+, 2013)
J/MNRAS/444/1157 : Members of ONC and Tau-Aur (Davies+, 2014)
J/ApJ/784/126 : IR photometry of all known members in Taurus (Esplin+, 2014)
J/ApJ/786/97 : Photospheric properties of T Tauri stars (Herczeg+, 2014)
J/ApJ/788/40 : Late-type targets in Taurus, ChaI & Upper Sco (Todorov+, 2014)
J/ApJ/799/155 : Sub-stellar companions in Taurus (Daemgen+, 2015)
J/ApJS/216/26 : T Tauri in Taurus-Auriga with GALEX (Gomez de Castro+, 2015)
J/ApJ/804/64 : Empirical and model parameters of 183 M dwarfs (Mann+, 2015)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 17 A17 --- 2MASS 2MASS name (JHHMMSSss+DDMMSSs)
19- 45 A27 --- Name Other Name
47- 51 A5 --- SpT MK Spectral Type
53- 54 I2 --- r_SpT Reference for SpT (see refs.dat file)
56- 59 F4.1 mag Av [-5/10]? Extinction at V mag
61- 62 I2 --- r_Av ? Reference for Av (see refs.dat file)
64- 68 F5.2 mag rpmag [4.6/22.5]? r' mag (1)
70- 74 A5 --- r_rpmag Reference(s) for rpmag (see refs.dat file)
76- 80 F5.2 mag Ksmag [4/15.5] 2MASS Ks magnitude (2)
83- 88 F6.1 mas/yr pmRA [-110/252]? Proper motion, in Right Ascension
91- 96 F6.1 mas/yr pmDE [-627/47]? Proper motion, in Declination
98-101 F4.1 mas/yr e_pm [0.5/6]? Uncertainty in proper motion
103-103 I1 --- r_pm ? Reference for proper motion, muRA, muDE
(see refs.dat file)
105-106 I2 --- Ref ? Binary Reference (see refs.dat file)
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Note (1): We obtained r' magnitudes for incomplete subsets of the sample from
the APASS (Henden+ 2012JAVSO..40..430H 2012JAVSO..40..430H ; see II/336),
CMC15 (Evans+ 2002A&A...395..347E 2002A&A...395..347E, see I/327), and
SDSS DR9 (Adelman-McCarthy+ 2012, V/139) catalogs.
For stars with magnitudes in multiple catalogs, we adopted the
unweighted mean of all available magnitudes.
We also use R magnitudes from the NOMAD survey
(Zacharias+ 2005, I/297) and from the QUEST survey of Taurus conducted
by Slesnick+ (2006, J/AJ/132/2665).
See section 2.2 for further explanations.
Note (2): All Ks magnitudes are from 2MASS Skrutskie+ (2006, VII/233)
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Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 17 A17 --- 2MASS 2MASS name (JHHMMSSss+DDMMSSs)
19- 45 A27 --- Name Other Name
47- 51 A5 --- SpT MK Spectral Type
53- 57 F5.1 0.1nm EWHa [-69/5] Literature Equivalent width, Hα,
in Angstrom units
59- 61 I3 --- r_EWHa Reference for EWHa (see refs.dat file)
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Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 17 A17 --- 2MASS 2MASS name (JHHMMSSss+DDMMSSs)
19- 33 A15 --- Name Other Name
35- 39 A5 --- SpT MK Spectral Type
41 A1 --- l_EWLi Limit flag on EWLi
42- 44 I3 0.1pm EWLi [0/820] Literature Equivalent width,
Lithium 6708Å, in milli-Angstrom units
46- 48 I3 --- r_EWLi Reference for EWLi (see refs.dat file)
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Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 17 A17 --- 2MASS 2MASS name (JHHMMSSss+DDMMSSs)
19- 33 A15 --- Name Other Name
35- 39 A5 --- SpT MK Spectral Type
41- 47 F7.3 km/s RVel [-17/50] Literature Radial Velocity
49- 51 I3 --- r_RVel Reference for RVel (see refs.dat file)
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Byte-by-byte Description of file: table5.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 17 A17 --- 2MASS 2MASS name (JHHMMSSss+DDMMSSs)
19- 45 A27 --- Name Other Name
47- 54 A8 "YYYYMMDD" Epoch Epoch, UT Date
56- 59 I4 s Tint [180/2700] Spectrum integration time
61- 63 I3 --- SNR [6/223] Spectrum signal-to-noise ratio at 6600Å
65- 69 F5.1 0.1nm EWHa [-84/2] Equivalent width, Hα,
in Angstrom units
71- 73 I3 0.1pm EWLi [0/612] Equivalent width, Lithium 6708Å,
in milli-Angstrom units
75- 78 F4.1 km/s RVel [11/21] Radial Velocity
80- 82 F3.1 km/s e_RVel [0.5/3] Uncertainty in RVel
84- 87 F4.1 km/s vsini [13/98] Rotational velocity, v*sin(i)
89- 91 F3.1 km/s e_vsini [0.6/5] Uncertainty in vsini
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Byte-by-byte Description of file: table6.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 17 A17 --- 2MASS 2MASS name (JHHMMSSss+DDMMSSs)
19- 33 A15 --- Name Other Name
35- 42 A8 "YYYYMMDD" Epoch Epoch, UT Date
44- 47 I4 --- Tint [50/1820] Spectrum integration time
49- 52 A4 --- SpT MK Spectral Type
54- 56 F3.1 mag Av [0/2.6] Extinction at V mag
58- 62 F5.1 0.1nm EWHa [-45/2] Equivalent width, Hα, Angstroms
64- 68 F5.3 --- Na8189 [0.88/0.99]? Gravity sensitive sodium index,
Slesnick+ (2006, J/AJ/131/3016)
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Byte-by-byte Description of file: table7.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 17 A17 --- 2MASS 2MASS name (JHHMMSSss+DDMMSSs)
19- 32 A14 --- Name Other Name
34- 37 A4 --- SpT MK Spectral Type
39- 42 F4.2 --- Na8189 [0.83/0.97] Gravity sensitive sodium index,
Slesnick+ (2006, J/AJ/131/3016)
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Byte-by-byte Description of file: table8.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 17 A17 --- 2MASS 2MASS name (JHHMMSSss+DDMMSSs)
19- 45 A27 --- Name Other Name
47 A1 --- Li Membership test, lithium
49 A1 --- G Membership test, low surface gravity
51 A1 --- HRD Membership test, location in HR diagram
53 A1 --- Ha Membership test, Hα
55- 56 A2 --- PM Membership test, proper motion
58- 59 A2 --- RV Membership test, radial velocity
61- 62 A2 --- Mm Membership test, final (3)
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Note (3): Membeship as follows:
Y = Confirmed Taurus member (160 occurrences)
Y? = Likely Taurus member (58 occurrences)
N? = Likely interloper (91 occurrences)
N = Confirmed interloper (69 occurrences)
? = Lack sufficient evidence to draw firm conclusions (18 occurrences)
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Byte-by-byte Description of file: refs.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- Ref Reference code
5- 23 A19 --- BibCode Bibcode of the reference
25- 50 A26 --- Auth First author's name
52- 90 A39 --- Comm Comment
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 06-Nov-2017