J/ApJ/769/21 Accretion luminosities of young stars from Pfβ (Salyk+, 2013)
Measuring protoplanetary disk accretion with HI Pfund β.
Salyk C., Herczeg G.J., Brown J.M., Blake G.A., Pontoppidan K.M.,
van Dishoeck E.F.
<Astrophys. J., 769, 21 (2013)>
=2013ApJ...769...21S 2013ApJ...769...21S
ADC_Keywords: YSOs ; Photometry, infrared ; Stars, masses ; Equivalent widths
Keywords: accretion, accretion disks; protoplanetary disks; stars: formation;
stars: pre-main sequence
Abstract:
In this work, we introduce the use of HI Pfund β (Pfβ;
4.6538µm) as a tracer of mass accretion from protoplanetary disks
onto young stars. Pfβ was serendipitously observed in NIRSPEC and
CRIRES surveys of CO fundamental emission, amounting to a sample size
of 120 young stars with detected Pfβ emission. Using a subsample
of disks with previously measured accretion luminosities, we show that
Pfβ line luminosity is well correlated with accretion luminosity
over a range of at least three orders of magnitude. We use this
correlation to derive accretion luminosities for all 120 targets, 65
of which are previously unreported in the literature. The conversion
from accretion luminosity to accretion rate is limited by the
availability of stellar mass and radius measurements; nevertheless, we
also report accretion rates for 67 targets, 16 previously unmeasured.
Our large sample size and our ability to probe high extinction values
allow for relatively unbiased comparisons between different types of
disks.
Description:
NIRSPEC observations were obtained with the Keck II telescope as part
of a large survey of CO rovibrational emission from young stars with
disks (see, e.g., Salyk et al. 2011ApJ...743..112S 2011ApJ...743..112S), spanning
2001-2011. Spectra were obtained in the high-resolution mode with
R∼25000, in the M-wide filter.
CRIRES observations were obtained with the Very Large Telescope (VLT)
as part of a large survey of CO rovibrational emission from young
stars with circumstellar disks (Pontoppidan et al. 2011Msngr.143...32P 2011Msngr.143...32P;
Brown et al. 2013ApJ...770...94B 2013ApJ...770...94B), including a significant sample of
embedded protostars (Herczeg et al. 2011A&A...533A.112H 2011A&A...533A.112H). Observations
were obtained with the 0.2" slit, resulting in a resolution of R∼90000,
between 2007 Apr-2009 Jan.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 52 194 Log of observations
table2.dat 40 120 Photometry
table3.dat 83 120 Stellar and disk parameters
table4.dat 58 120 Derived Pfβ accretion parameters;
equivalent widths of other accretion tracers
table5.dat 53 120 Literature accretion luminosities and
mass accretion rates
refs.dat 72 156 References
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See also:
II/237 : Stellar Photometry in Johnson's 11-color system (Ducati, 2002)
I/239 : The Hipparcos and Tycho Catalogues (ESA 1997)
II/62 : Catalogue of Extinction Data (Neckel+, 1980)
J/ApJS/186/259 : Taurus Spitzer survey: new candidate members (Rebull+, 2010)
J/A+A/508/309 : Spectral atlas of HD 50138 (Borges Fernandes+, 2009)
J/ApJS/181/321 : Properties of Spitzer c2d dark clouds (Evans+, 2009)
J/ApJ/703/1964 : Spectra of three nearby star-forming regions (Furlan+, 2009)
J/ApJS/177/551 : Spitzer c2d survey of Lupus dark clouds (Merin+, 2008)
J/ApJ/667/308 : Weak-line T Tauri in Spitzer c2d Survey. II. (Cieza+, 2007)
J/ApJ/653/657 : Spectroscopic obs. of Herbig Ae/Be stars (Manoj+, 2006)
J/ApJ/647/1180 : Infrared photometry of Taurus SFR (Luhman+, 2006)
J/ApJ/636/932 : Mid-infrared survey of T Tauri stars (McCabe+, 2006)
J/AJ/131/1574 : Infrared photometry of IC348 members (Lada+, 2006)
J/A+A/452/245 : Near-IR photometry of PMS stars in rho Oph (Natta+, 2006)
J/ApJ/630/381 : Mid-IR imaging in ρ Oph (Barsony+, 2005)
J/AJ/130/1145 : YSO near-infrared properties (Doppmann+, 2005)
J/AJ/129/856 : Herbig Ae/Be in nearby OB associations (Hernandez+, 2005)
J/A+A/422/141 : IRAS 08211-4158 cluster IR phot. (Caratti o Garatti+, 2004)
J/ApJS/147/305 : IUE atlas of pre-main-sequence stars (Valenti+, 2003)
J/AJ/126/2971 : UBVRI photometry of 131 Herbig Ae/Be (Vieira+, 2003)
J/A+A/378/116 : Classification of Vega-type and PMS stars (Mora+, 2001)
J/A+A/372/173 : ISOCAM obs. of the rho Ophiuchi cloud (Bontemps+, 2001)
J/A+A/365/90 : NIR H lines in TTS (Folha+, 2001)
J/MNRAS/310/210 : Stellar composition of CMa R1 (Shevchenko+, 1999)
J/A+A/299/89 : COYOTES II (Bouvier+, 1995)
J/ApJS/101/117 : UBVRIJHKLMNQ photometry in Taurus-Auriga (Kenyon+ 1995)
J/ApJS/94/615 : Molecular outflow sources (Hodapp, 1994)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 7 A7 --- Inst Instrument used in the observation
9- 23 A15 --- Star Star identifier
25- 35 A11 "YYYY/MM/DD" Date Date of the observation
37- 40 I4 s Exp Exposure time
42- 44 I3 km/s VDop Earth-induced Doppler shift toward source
position
46- 52 A7 --- Std Standard star identifier
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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- 15 A15 --- Star Star identifier
17- 20 F4.2 mag Mmag [2.4/8.1]? M-band magnitude
22 A1 --- f_Mmag [ab] Flag on Mmag (1)
24- 27 F4.2 mag [4.5] ? Spitzer/IRAC 4.5 micron band magnitude
29- 32 F4.2 mag [5.8] [3.4/9.8]? Spitzer/IRAC 5.8um band magnitude
34- 40 A7 --- Ref Reference(s) (see refs.dat file)
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Note (1): Flag as follows:
a = Although other photometric measurements are available for this source,
we use the spectroscopically-derived measurements from
Goto et al. (2011ApJ...728....5G 2011ApJ...728....5G) as EX Lup was in outburst during the
observations presented here, and thus several magnitudes brighter than
in its quiescent state.
b = Corrected for observed relative fluxes of IRS 44 E and IRS 44 W from
Herczeg et al. (2011A&A...533A.112H 2011A&A...533A.112H).
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 15 A15 --- Star Star identifier
17- 20 I4 pc Dist [56/2200] Distance
22- 26 A5 --- SpT MK spectral type
28- 32 I5 K Teff [1148/30200]? Stellar effective temperature
34- 40 F7.2 Lsun Lum [0.1/5750]? Stellar luminosity
42- 45 F4.2 Rsun Rad [0.8/9.3]? Stellar radius
47- 50 F4.2 Msun Mass [0.2/6]? Stellar mass
52- 56 F5.2 mag Av [0/38]? V band extinction
58- 67 A10 --- r_Star Stellar parameter reference(s)
(see refs.dat file)
69- 71 A3 --- Stage Stellar stage (2)
73 A1 --- f_Stage Flag on Stage (3)
75- 79 A5 --- r_Stage Reference(s) for Stage (see refs.dat file)
81- 83 A3 --- Inst Instrument used in observation (N=NIRSPEC,
C=CRIRES)
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Note (2): IIt refers to known transitional disks with inner disk cavities.
Note (3): Flag as follows:
c = CK 4 (SSTc2d J182958.19+011521.8) has a weak ice absorption feature
in NIRSPEC spectra, but its spectral slope, bolometric temperature and
lack of extended millimeter emission suggest that it is a stage II
object (Evans et al. 2009, J/ApJS/181/321).
d = Haro 6-13 is often classified as a borderline stage I/II object
(Teixeira & Emerson 1999A&A...351..303T 1999A&A...351..303T; White & Hillenbrand
2004ApJ...616..998W 2004ApJ...616..998W).
e = HL Tau is often classified as a borderline stage I/II object
(Teixeira & Emerson 1999A&A...351..303T 1999A&A...351..303T; White & Hillenbrand
2004ApJ...616..998W 2004ApJ...616..998W), but is classified as stage I by Herczeg et al.
(2011A&A...533A.112H 2011A&A...533A.112H) due to the presence of an extended envelope,
cold compact gas and molecular outflow.
f = This source is borderline stage I/II based on its "flat" spectral
slope and bolometric temperature, and the presence of an extended
envelope (Evans et al. 2009, J/ApJS/181/321). However, its M-band
spectrum shows no evidence for CO ice, and we adopt a stage II
classification.
g = IRS 48 has a weak CO ice feature in its CRIRES spectrum, but appears
to be an evolved stage II disk, perhaps transitioning to stage III
(Brown et al. 2012ApJ...744..116B 2012ApJ...744..116B).
h = IRS 51 is a flat spectrum source with a bolometric temperature in the
Class II range, but with evidence of an extended envelope
(Evans et al. 2009, J/ApJS/181/321). We adopt a stage I classification
due to its prominent M-band ice feature.
i = Assuming the properties of SSTc2d +J162659.10-243503.3
(Evans et al. 2009, J/ApJS/181/321).
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 15 A15 --- Star Star identifier
17- 22 F6.2 0.1nm EWPfb [-47/-0.5] Pfund β equivalent width at
4.6538µm; in Angstroms (4)
24- 28 F5.2 [Lsun] logLPfb [-5.3/-0.6] Log Pfβ luminosity
30- 34 F5.2 [Lsun] logLacc Log accretion luminosity (5)
36- 40 F5.2 [Msun/yr] logMacc [-8.7/-5.6]? Log mass accretion rate
42- 47 F6.2 0.1nm EWBrg ? Bracketγ equivalent width (Å)
49- 54 F6.2 0.1nm EWPab ? Paschenβ equivalent width (Å)
56- 58 I3 --- Ref4 ? Reference (see refs.dat file)
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Note (4): Adjusted for photometry and extinction, as described in text.
Assumes distances in Table 3. If both NIRSPEC and CRIRES data were
available, the average value is shown.
Note (5): Calculated assuming Lacc=0.8GMstardot{M}/Rstar
(Gullbring et al. 1998ApJ...492..323G 1998ApJ...492..323G). If not shown in Table 3,
Rstar is derived from Lstar and Tstar assuming
Lstar=4πRstar2σTstar4. Missing data
indicate that either the stellar radius or mass is not available.
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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1- 15 A15 --- Star Star name
17- 24 F8.3 Lsun Lacc [0.01/1510]? Accretion luminosity
26 A1 --- f_Lacc [b] Flag on Lacc (1)
28- 30 I3 --- r_Lacc ? Reference for Lacc (see refs.dat file)
32- 43 A12 --- Method Method used (2)
45- 49 F5.2 [Msun/yr] logMacc [-8.9/-4.1]? Log of mass accretion rate
51- 53 I3 --- r_logMacc ? Reference for logMdot (see refs.dat file)
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Note (1):
b = This and all other Taurus accretion luminosities from
Valenti et al. (1993AJ....106.2024V 1993AJ....106.2024V) scaled to 140pc distance.
Note (2): Description of abbreviations are as follows.
UV Exc. = measurement of UV excess emission spectrum;
Br γ = use of Brγ-accretion luminosity relationship;
Pa β = use of Paβ-accretion luminosity relationship;
U-Band Phot. = use of optical U-band photometric data;
Balmer depth = based on relationship between the mass accretion rate and the
excess in the Balmer discontinuity derived by
Muzerolle et al. (2004ApJ...617..406M 2004ApJ...617..406M).
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Byte-by-byte Description of file: refs.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Ref Reference code
5- 23 A19 --- BibCode Bibcode
25- 51 A27 --- Aut Author's name(s)
53- 72 A20 --- Comm Comment (VizieR catalog reference)
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 03-Dec-2014