J/ApJ/799/136 IN-SYNC. II. Candidate young stars in NGC 1333 (Foster+, 2015)
IN-SYNC.
II. Virial stars from subvirial cores --the velocity dispersion of embedded
pre-main-sequence stars in NGC 1333.
Foster J.B., Cottaar M., Covey K.R., Arce H.G., Meyer M.R., Nidever D.L.,
Stassun K.G., Tan J.C., Chojnowski S.D., da Rio N., Flaherty K.M.,
Rebull L., Frinchaboy P.M., Majewski S.R., Skrutskie M., Wilson J.C.,
Zasowski G.
<Astrophys. J., 799, 136 (2015)>
=2015ApJ...799..136F 2015ApJ...799..136F
ADC_Keywords: YSOs ; Spectra, infrared ; Radial velocities ;
Rotational velocities ; Effective temperatures
Keywords: ISM: kinematics and dynamics; stars: kinematics and dynamics;
stars: pre-main sequence; stars: protostars
Abstract:
The initial velocity dispersion of newborn stars is a major
unconstrained aspect of star formation theory. Using near-infrared
spectra obtained with the APOGEE spectrograph, we show that the
velocity dispersion of young (1-2Myr) stars in NGC 1333 is
0.92±0.12km/s after correcting for measurement uncertainties and the
effect of binaries. This velocity dispersion is consistent with the
virial velocity of the region and the diffuse gas velocity dispersion,
but significantly larger than the velocity dispersion of the dense,
star-forming cores, which have a subvirial velocity dispersion of
0.5km/s. Since the NGC 1333 cluster is dynamically young and deeply
embedded, this measurement provides a strong constraint on the initial
velocity dispersion of newly formed stars. We propose that the
difference in velocity dispersion between stars and dense cores may be
due to the influence of a 70µG magnetic field acting on the dense
cores or be the signature of a cluster with initial substructure
undergoing global collapse.
Description:
Spectra were obtained using the APOGEE multiobject spectrograph
(1.51-1.69um with R∼22500). The details of the data reduction and
spectral fitting are presented in Paper I (INfrared Spectra of Young
Nebulous Clusters (IN-SYNC); Cottaar et al. (2014, J/ApJ/794/125).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 56 205 Candidate young stars in NGC 1333
table2.dat 99 361 Fit parameters for all observed APOGEE Spectra
in NGC 1333 (108 stars)
table3.dat 78 108 Average parameters for all stars in NGC 1333
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See also:
II/332 : c2d Spitzer final data release (DR4) (Evans+, 2003)
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
J/ApJ/794/125 : IN-SYNC. I. APOGEE spectra in IC348+Pleiades (Cottaar+, 2014)
J/ApJS/214/7 : CO survey of molecular clouds. IV. NGC 1333 (Bieging+, 2014)
J/MNRAS/434/806 : Pre-main-sequence isochrones. II. SFR (Bell+, 2013)
J/AJ/146/133 : Stellar data from SDSS-III APOGEE DR10 (Meszaros+, 2013)
J/ApJ/774/22 : CO observations of YSOs in NGC 1333 (Plunkett+, 2013)
J/ApJ/744/6 : SONYC census of low-mass objects in NGC1333 (Scholz+, 2012)
J/ApJS/190/1 : A survey of stellar families (Raghavan+, 2010)
J/AJ/140/266 : NGC 1333 X-ray luminous YSOs properties (Winston+, 2010)
J/ApJ/692/973 : Protostars in Perseus, Serpens and Ophiuchus (Enoch+, 2009)
J/ApJS/184/18 : Spitzer survey of young stellar clusters (Gutermuth+, 2009)
J/AJ/136/1372 : Very low-mass YSOs in NGC 1333 (Oasa+, 2008)
J/ApJS/179/249 : Low-luminosity embedded protostar population (Dunham+, 2008)
J/ApJS/175/509 : Ammonia spectral atlas in Perseus (Rosolowsky+, 2008)
J/ApJ/674/336 : Spitzer observations of NGC 1333 (Gutermuth+, 2008)
J/ApJ/668/1042 : Dense cores in Perseus molecular cloud (Kirk+, 2007)
J/AJ/127/1131 : NGC 1333 low-mass stars infrared photometry (Wilking+, 2004)
J/A+A/401/543 : XMM-Newton observations of NGC 1333 (Preibisch, 2003)
J/ApJ/575/354 : Young stellar objects in the NGC 1333 (Getman+, 2002)
J/AJ/111/1964 : JHK photometry of NGC1333 (Lada+, 1996)
J/A+AS/106/165 : Near-IR imaging photometry of NGC 1333 (Aspin+ 1994)
J/A+A/291/943 : Protostellar cores (Ossenkopf+, 1994)
http://www.sdss3.org/ : SDSS-III home page
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Seq [1/205] Running sequence number
5- 6 A2 --- --- [2M]
7- 22 A16 --- 2MASS 2MASS identifier (HHMMSSss+DDMMSSs; J2000)
24- 30 F7.4 deg RAdeg Right Ascension in decimal degrees (J2000)
32- 38 F7.4 deg DEdeg Declination in decimal degrees (J2000)
40- 44 F5.2 mag Jmag [8.1/18.6] 2MASS J band magnitude
46- 50 F5.2 mag Hmag [7.7/17.8] 2MASS H band magnitude
52- 56 F5.2 mag Ksmag [7.1/15.7] 2MASS KS band magnitude
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Seq [1/204] Object identifier
5- 15 F11.5 d MJD Modified Julian Date of the observation
17- 24 F8.2 km/s RVel [-1456/390] Fit radial velocity
26- 32 F7.2 km/s e_RVel [0.02/2931] Uncertainty in RVel
34- 40 F7.2 km/s vsini [0.01/4189] Fit projected rotational velocity
42- 48 F7.2 km/s e_vsini [0.08/3030] Uncertainty in vsini
50- 56 F7.2 K Teff [400/7000] Fit effective temperature
58- 64 F7.2 K e_Teff [0/5130] Uncertainty in Teff
66- 70 F5.2 [cm/s2] log(g) [-0.5/5.5] Log of fit surface gravity
72- 75 F4.2 [cm/s2] e_log(g) [0/4.5] Uncertainty in log(g)
77- 80 F4.2 --- rH [0/7.9] Fit H-hand veiling value
82- 86 F5.2 --- e_rH [0/22] Uncertainty in rH
88- 95 F8.1 --- chi2 [0.1/135006] Reduced Χ2 value
97- 99 I3 --- S/N [0/420] Signal-to-Noise
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Seq [1/204] Object identifier
5- 11 F7.2 km/s RVel [-309.1/98]? Fit radial velocity
13- 19 F7.2 km/s e_RVel [0.08/1543]? Uncertainty in RVel
21- 26 F6.2 km/s vsini [2/587.1]? Fit projected rotational velocity
28- 34 F7.2 km/s e_vsini [0.1/1293]? Uncertainty in vsini
36- 39 I4 K Teff [1900/7000]? Fit effective temperature
41- 44 I4 K e_Teff [0/1030]? Uncertainty in Teff
46- 50 F5.2 [cm/s2] log(g) [-0.3/5.4]? Log of fit surface gravity
52- 55 F4.2 [cm/s2] e_log(g) [0.02/4.5]? Uncertainty in log(g)
57- 60 F4.2 --- rH [0/3.4]? Fit H-hand veiling value
62- 66 F5.2 --- e_rH [0/12]? Uncertainty in rH
68- 72 F5.2 mag JMag [-0.6/10.1]? Absolute J band magnitude
74 I1 --- Nobs [1/7] Number of observations
76 I1 --- Ngood [0/7] Number of good observations (1)
78 I1 --- Var [0/1] Variable flag (1=variable) (2)
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Note (1): Number of spectra meeting the quality criteria given in the text.
Note (2): Binary flag indicating if the source has a significantly variable
radial velocity as defined in the text (1 for variable,
0 for non-variable).
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History:
From electronic version of the journal
References:
Cottaar et al. Paper I. 2014ApJ...794..125C 2014ApJ...794..125C Cat. J/ApJ/794/125
Cottaar et al. Paper III. 2015ApJ...807...27C 2015ApJ...807...27C Cat. J/ApJ/807/27
Da Rio et al. Paper IV. 2016ApJ...818...59D 2016ApJ...818...59D Cat. J/ApJ/818/59
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 16-Jun-2015