J/ApJS/238/19 VANDAM IV. Free-free emission from protostars (Tychoniec+, 2018)
The VLA Nascent Disk and Multiplicity Survey of Perseus protostars (VANDAM).
IV. Free-free emission from protostars: links to infrared properties, outflow
tracers, and protostellar disk masses.
Tychoniec L., Tobin J.J., Karska A., Chandler C., Dunham M.M., Harris R.J.,
Kratter K.M., Li Z.-Y., Looney L.W., Melis C., Perez L.M., Sadavoy S.I.,
Segura-Cox D., van Dishoeck E.F.
<Astrophys. J. Suppl. Ser., 238, 19 (2018)>
=2018ApJS..238...19T 2018ApJS..238...19T
ADC_Keywords: Molecular clouds; YSOs; Radio continuum; Surveys
Keywords: protoplanetary disks ; radio continuum: stars ; stars: formation ;
stars: protostars ; stars: winds, outflows ;
techniques: interferometric
Abstract:
Emission from protostars at centimeter radio wavelengths has been
shown to trace the free-free emission arising from ionizing shocks as
a result of jets and outflows driven by protostars. Therefore,
measuring properties of protostars at radio frequencies can provide
valuable insights into the nature of their outflows and jets. We
present a C-band (4.1 and 6.4cm) survey of all known protostars
(Class0 and ClassI) in Perseus as part of the VLA Nascent Disk and
Multiplicity (VANDAM) Survey. We examine the known correlations
between radio flux density and protostellar parameters, such as
bolometric luminosity and outflow force, for our sample. We also
investigate the relationship between radio flux density and
far-infrared line luminosities from Herschel. We show that free-free
emission most likely originates from J-type shocks; however, the large
scatter indicates that those two types of emission probe different
time and spatial scales. Using C-band fluxes, we removed an estimation
of free-free contamination from the corresponding Ka- band (9mm) flux
densities that primarily probe dust emission from embedded disks. We
find that the compact (<1") dust emission is lower for Class I sources
(median dust mass 96M⊕) relative to Class 0 (248M⊕),
but several times higher than in Class II (5-15M⊕). If this
compact dust emission is tracing primarily the embedded disk, as is
likely for many sources, this result provides evidence of decreasing
disk masses with protostellar evolution, with sufficient mass for
forming giant planet cores primarily at early times.
Description:
We conducted C-band observations with the VLA in A-configuration
between 2014 February 28 and 2014 April 12. The C-band data (4.1 and
6.4cm) were taken in 8 bit mode, yielding 2GHz of bandwidth divided
into sixteen 128MHz sub-bands with 2MHz channels and full polarization
products. We centered our 1GHz basebands at 4.7 and 7.4GHz, thus
avoiding some persistent radio frequency interference in these bands.
Further details of the calibration and data reduction of the C-band
observations are described in the previous VANDAM papers
(Tobin+ 2015ApJ...798...61T 2015ApJ...798...61T ; Tychoniec+ 2018ApJ...852...18T 2018ApJ...852...18T).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 87 95 Protostars of the VLA Nascent Disk and Multiplicity
(VANDAM) survey
table3.dat 160 143 C-band observation results
table4.dat 160 24 Young stellar object candidates
table5.dat 160 59 Known non-protostellar sources
table6.dat 160 12 New detections reported in Pech+ (2016, J/ApJ/818/116)
table7.dat 160 490 New detections from VANDAM survey
table10.dat 76 143 Protostellar disk masses
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See also:
VIII/65 : 1.4GHz NRAO VLA Sky Survey (NVSS) (Condon+ 1998)
J/A+AS/106/165 : Near-IR imaging photometry of NGC 1333 (Aspin+ 1994)
J/A+A/291/943 : Protostellar cores (Ossenkopf+, 1994)
J/ApJS/125/427 : Radio sources in HH 7-11 region (Rodriguez+, 1999)
J/AJ/122/866 : X-ray sources in IC 348 from Chandra (Preibisch+, 2001)
J/ApJ/575/354 : Young stellar objects in the NGC 1333 (Getman+, 2002)
J/A+A/409/147 : J magnitude of IC 348 brown dwarfs (Preibisch+, 2003)
J/AJ/127/1131 : NGC 1333 low-mass stars infrared photometry (Wilking+, 2004)
J/A+A/426/503 : High velocity molecular outflows (Update) (Wu+, 2004)
J/ApJ/638/293 : 1.1mm sources in the Perseus Molecular Cloud (Enoch+, 2006)
J/A+A/472/187 : CO outflows towards submm cores in Perseus (Hatchell+, 2007)
J/ApJ/668/1042 : Dense cores in Perseus molecular cloud (Kirk+, 2007)
J/AJ/135/2496 : Near-IR survey of Class I protostars (Connelley+, 2008)
J/MNRAS/387/954 : H2 imaging of NGC 1333, L1455, L1448 and B1 (Davis+, 2008)
J/ApJ/674/336 : Spitzer observations of NGC 1333 (Gutermuth+, 2008)
J/AJ/136/1372 : Very low-mass YSOs in NGC 1333 (Oasa+, 2008)
J/ApJ/692/973 : Protostars in Perseus, Serpens and Ophiuchus (Enoch+, 2009)
J/ApJS/181/321 : Properties of Spitzer c2d dark clouds (Evans+, 2009)
J/AJ/140/266 : NGC 1333 X-ray luminous YSOs properties (Winston+, 2010)
J/ApJ/771/129 : Submillimetric Class II sources of Taurus (Andrews+, 2013)
J/ApJ/775/63 : Gould's Belt VLA Survey. I. Ophiuchus complex (Dzib+, 2013)
J/A+A/572/A21 : H2O spectra of nearby Class 0/I protostars (Mottram+, 2014)
J/ApJ/801/91 : Gould's Belt Very Large Array survey IV. Taurus (Dzib+, 2015)
J/A+A/577/L2 : Barnard 1b-N and 1b-S nascent bipolar outflows (Gerin+, 2015)
J/A+A/576/A109 : YSOs APEX-CHAMP+ high-J CO maps (Yildiz+, 2015)
J/AJ/150/40 : The Spitzer c2d survey of clouds. XII. Perseus (Young+, 2015)
J/ApJ/828/46 : ALMA survey of Lupus protoplanetary disks I. (Ansdell+, 2016)
J/ApJ/827/142 : ALMA obs. of GKM stars in Upper Sco (Barenfeld+, 2016)
J/ApJ/831/125 : 887µm obs. of ChaI star-forming region (Pascucci+, 2016)
J/ApJ/818/116 : Gould's Belt VLA survey. V. Perseus region (Pech+, 2016)
J/ApJ/818/73 : Study of protostars in Perseus molecular cloud (Tobin+, 2016)
J/AJ/153/240 : Protoplanetary disk ALMA survey in sigma Ori (Ansdell+, 2017)
J/ApJS/230/7 : Spectral flux densities from 50MHz to 50GHz (Perley+, 2017)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 22 A22 --- Name Identifier (1)
24- 25 I2 h RAh [3] Hour of Right Ascension (J2000) (2)
27- 28 I2 min RAm [25/47] Minute of Right Ascension (J2000) (2)
30- 35 F6.3 s RAs Second of Right Ascension (J2000) (2)
37 A1 --- DE- [+] Sign of the Declination (J2000)(2)
38- 39 I2 deg DEd [30/32] Degree of Declination (J2000) (2)
41- 42 I2 arcmin DEm Arcminute of Declination (J2000) (2)
44- 49 F6.3 arcsec DEs Arcsecond of Declination (J2000) (2)
51- 56 A6 --- Field Field identifier (3)
58 A1 --- Det6.4 Detected at 6.4cm? (Y)es/(N)o
60 A1 --- Det4.1 Detected at 4.1cm? (Y)es/(N)o
62- 65 A4 --- Class Protostar class
67- 70 F4.1 Lsun Lbol [0/32.5]? Bolometric luminosity (4)
72- 74 F3.1 Lsun e_Lbol [0/7.1]? Uncertainty in Lbol
76- 81 F6.1 K Tbol [14/1300]? Bolometric temperature(4)
83- 87 F5.1 K e_Tbol [1/240]? Uncertainty in Tbol
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Note (1):
Per-emb-XX (Enoch+ 2009, J/ApJ/692/973 ; <[EES2009] Per-emb NN> in Simbad),
EDJ2009-XXX (Evans+ 2009, J/ApJS/181/321 ; <[EDJ2009] NNNN> in Simbad),
SVSX (Strom+ 1976AJ.....81..314S 1976AJ.....81..314S ; <[SVS76] NGC 1333 NN> in Simbad).
Note (2): Coordinates from VANDAM Ka-band observations
(Tobin+ 2016Natur.538..483T 2016Natur.538..483T).
Note (3): Name of the observational field where source was closest to the
peak of the primary beam response.
Note (4): Values from Enoch+ (2009, J/ApJ/692/973),
Sadavoy+ (2014ApJ...787L..18S 2014ApJ...787L..18S) and Young+ (2015, J/AJ/150/40).
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Byte-by-byte Description of file: table[34567].dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 A3 --- Type Type (only for table 5)
5- 26 A22 --- Name Identifier
28- 29 I2 h RAh [3] Hour of Right Ascension (J2000)
31- 32 I2 min RAm [24/47] Minute of Right Ascension (J2000)
34- 39 F6.3 s RAs Second of Right Ascension (J2000)
41 A1 --- DE- [+] Sign of the Declination (J2000)
42- 43 I2 deg DEd [30/32] Degree of Declination (J2000)
45- 46 I2 arcmin DEm Arcminute of Declination (J2000)
48- 53 F6.3 arcsec DEs Arcsecond of Declination (J2000)
55 A1 --- l_Fint6.4 Limit flag on Fint6.4
56- 63 F8.4 mJy Fint6.4 [0.01/63]? Integrated 6.4cm flux density (1)
65- 72 F8.4 mJy e_Fint6.4 [0.002/2]? Uncertainty in Fint6.4
74 A1 --- l_Fpk6.4 Limit flag on Fpeak6.4
75- 82 F8.4 mJy/beam Fpk6.4 [0.01/43]? Peak 6.4cm value of flux density
on source
84- 91 F8.4 mJy/beam RMS6.4 [0.004/0.1]? Root-Mean-Square of 6.4cm image
93 A1 --- l_Fint4.1 Limit flag on Fint4.1
94-101 F8.4 mJy Fint4.1 [0.006/17]? Integrated 4.1cm flux density (1)
103-110 F8.4 mJy e_Fint4.1 [0.003/0.7]? Uncertainty in Fint4.1
112 A1 --- l_Fpk4.1 Limit flag on Fpeak4.1
113-120 F8.4 mJy/beam Fpk4.1 [0.01/6]? Peak 4.1cm value of flux density
on source
122-129 F8.4 mJy/beam RMS4.1 [0.003/0.6]? Root-Mean-Square of 4.1cm image
131 A1 --- l_SpIndInt Limit flag on SpIndInt
132-138 F7.2 --- SpIndInt [-6/8.1]? Spectral index calculated
with the integrated flux
140-143 F4.2 --- e_SpIndInt [0/3.4]? Uncertainty in SpIndInt
145 A1 --- l_SpIndPk Limit flag on SpIndPeak
146-153 F8.2 --- SpIndPk [-7/7.2]? Spectral index calculated
with the peak flux
155-160 F6.2 --- e_SpIndPk [0/1]? Uncertainty in SpIndPeak
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Note (1): Resulting from area under 2D Gaussian fit to the source.
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Byte-by-byte Description of file: table10.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 22 A22 --- Name Identifier
24 A1 --- l_F9 Limit flag on F9
25- 31 F7.2 mJy F9 [0.02/8]? Integrated 9mm flux density
33 A1 --- l_Fc9 Limit flag on Fc9
34- 40 F7.2 mJy Fc9 [0/6.7]? Corrected 9mm flux density
42- 44 I3 % Fd/F9 [0/100]? Ratio of dust to 9mm fluxes
46 A1 --- l_Mg+d Limit to Mg+d
47- 53 F7.3 Msun Mg+d [0.004/1.7]? Gas and dust masses from 9mm data
55- 59 F5.3 Msun e_Mg+d [0.002/0.03]? Uncertainty in Mg+d
61 A1 --- l_Mcg+d Limit to Mcg+d
62- 68 F7.3 Msun Mcg+d [0/1.5]? Gas and dust masses from corrected
9mm data
70- 74 F5.3 Msun e_Mcg+d [0.002/0.03]? Uncertainty in Mcg+d
76 A1 --- Flag Flag (3)
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Note (3): Flags d, e, and f, were treated as upper limits in the analysis.
a = regular fit;
b = one of the C-band channels with non-detections;
c = excess of the free-free emission;
d = non-detection in both C-band channels;
e = non-detection in both Ka- and C-band;
f = flat or negative spectral index in Ka-band.
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History:
From electronic version of the journal
References:
Segura-Cox et al. 2016ApJ...817L..14S 2016ApJ...817L..14S
Tobin et al. Paper I. 2015ApJ...798...61T 2015ApJ...798...61T
Tobin et al. Paper II. 2016ApJ...818...73T 2016ApJ...818...73T Cat. J/ApJ/818/73
Tychoniec et al. Paper III. 2018ApJ...852...18T 2018ApJ...852...18T
Tychoniec et al. Paper IV. 2018ApJS..238...19T 2018ApJS..238...19T This catalog
Segura-Cox et al. Paper V. 2018ApJ...866..161S 2018ApJ...866..161S
Tobin et al. Paper VI. 2018ApJ...867...43T 2018ApJ...867...43T
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 20-Nov-2018