J/ApJ/831/73 Galactic MCs associated with HII regions (Vutisalchavakul+, 2016) ================================================================================ Star formation relations in the Milky Way. Vutisalchavakul N., Evans II N.J., Heyer M. =2016ApJ...831...73V (SIMBAD/NED BibCode) ================================================================================ ADC_Keywords: Molecular clouds ; H II regions ; Radio lines ; Infrared sources ; Millimetric/submm sources ; Galactic plane ; Velocity dispersion Keywords: galaxies: star formation; H II regions; stars: formation Abstract: The relations between star formation and properties of molecular clouds (MCs) are studied based on a sample of star-forming regions in the Galactic Plane. Sources were selected by having radio recombination lines to provide identification of associated MCs and dense clumps. Radio continuum emission and mid-infrared emission were used to determine star formation rates (SFRs), while ^13^CO and submillimeter dust continuum emission were used to obtain the masses of molecular and dense gas, respectively. We test whether total molecular gas or dense gas provides the best predictor of SFR. We also test two specific theoretical models, one relying on the molecular mass divided by the free-fall time, the other using the free-fall time divided by the crossing time. Neither is supported by the data. The data are also compared to those from nearby star-forming regions and extragalactic data. The star formation "efficiency," defined as SFR divided by mass, spreads over a large range when the mass refers to molecular gas; the standard deviation of the log of the efficiency decreases by a factor of three when the mass of relatively dense molecular gas is used rather than the mass of all of the molecular gas. Description: In this paper, we collect data from surveys of radio recombination lines (RRLs), radio continuum emission, and MIR emission to measure SFR, from ^13^CO spectroscopy to evaluate molecular cloud (MC) properties, and from millimeter dust continuum emission to trace the dense gas component. See section 2 for the data sources. File Summary: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file table1.dat 52 66 Radio recombination line sources table2.dat 45 66 Star formation rates table3.dat 89 66 The ^13^CO derived molecular properties table4.dat 59 64 BGPS-derived dense gas properties -------------------------------------------------------------------------------- See also: J/A+A/588/A104 : Molecular clouds and star formation (Gong+, 2016) J/A+A/588/A29 : Star formation in massive clumps in Milky Way (Heyer+, 2016) J/ApJ/805/157 : BGPS. XIII. Mass functions (Ellsworth-Bowers+, 2015) J/ApJ/805/31 : IR-radio luminosities + surface densities of gal. (Liu+, 2015) J/ApJS/212/1 : The WISE catalog of Galactic HII regions (Anderson+, 2014) J/ApJ/780/173 : Masses of giant molecular clouds in MW (Battisti+, 2014) J/ApJS/209/2 : The BGPS. X. Dense molecular gas (Shirley+, 2013) J/MNRAS/431/1587 : GRS/BGPS sources in Galactic Plane (Eden+, 2013) J/ApJ/754/62 : HRDS III. HII region kinematic distances (Anderson+, 2012) J/ApJS/195/14 : The BGPS. V. (Schlingman+, 2011) J/ApJ/741/110 : The BGPS. VII. Massive star-forming regions (Dunham+, 2011) J/ApJ/723/1019 : Galactic SFR and gas surface densities (Heiderman+, 2010) J/ApJ/723/492 : Properties of GRS molecular clouds (Roman-Duval+, 2010) J/ApJS/188/123 : The Bolocam Galactic Plane Survey. II. (Rosolowsky+, 2010) J/ApJS/184/1 : Molecular clouds in the LMC by NANTEN. II. (Kawamura+, 2009) J/ApJS/181/321 : Properties of Spitzer c2d dark clouds (Evans+, 2009) J/A+A/291/943 : Protostellar cores (Ossenkopf+, 1994) Byte-by-byte Description of file: table1.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 15 A15 --- ID WISE identifier (GLLL.lll+BB.bbb) (G1) 17- 22 F6.3 deg GLON Galactic longitude 24- 29 F6.3 deg GLAT Galactic latitude 31- 35 F5.1 km/s Vel [4/104] Radio recombination line velocity 37- 40 F4.1 kpc Dist [1/14] Distance 42- 44 F3.1 kpc e_Dist [0.1/2] The 1{sigma} uncertainty in Dist 46- 48 F3.1 kpc RGal [4/8] Galactic radius 50 I1 --- r_Vel Reference code for Vel (1) 52 I1 --- r_Dist Reference code for Dist (1) -------------------------------------------------------------------------------- Note (1): Reference as follows: 1 = Anderson et al. (2014, J/ApJS/212/1); 2 = Battisti & Heyer (2014, J/ApJ/780/173); 3 = Ellsworth-Bowers et al. (2015, J/ApJ/805/157). -------------------------------------------------------------------------------- Byte-by-byte Description of file: table2.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 15 A15 --- ID WISE identifier (GLLL.lll+BB.bbb) (G1) 17- 23 F7.2 Msun/Myr SFR-Rad [0.07/1220] Star Formation Rate from Radio 25- 30 F6.2 Msun/Myr e_SFR-Rad [0.01/122] The 1{sigma} error in SFR-Rad 32- 38 F7.2 Msun/Myr SFR-MIR [0/1112] Star Formation Rate from Mid-IR 40- 45 F6.2 Msun/Myr e_SFR-MIR [0/112] The 1{sigma} error in SFR-MIR -------------------------------------------------------------------------------- Byte-by-byte Description of file: table3.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 15 A15 --- ID WISE identifier (GLLL.lll+BB.bbb) (G1) 17 I1 --- Type Type code (2) 19- 23 F5.2 pc rCloud [2/34] Cloud effective radius 25- 28 F4.2 pc e_rCloud [0.01/9] The 1{sigma} error in rCloud 30- 33 F4.2 km/s delv [0.6/4] The 1-dimensional velocity dispersion 35- 38 F4.2 km/s e_delv [0.01/2] The 1{sigma} error in delv 40- 44 F5.1 kMsun MCloud [1/319] Cloud mass 46- 50 F5.1 kMsun e_MCloud [0.5/129] The 1{sigma} error in MCloud 52- 56 F5.1 kMsun MVir [2/275] Cloud virial mass 58- 61 F4.1 kMsun e_MVir [0.3/96] The 1{sigma} error in MVir 63- 66 F4.2 --- alpha [0.02/6] Virial parameter; MVir/MCloud 68- 71 F4.2 --- e_alpha [0.02/3] The 1{sigma} error in alpha 73- 76 I4 cm-3 nCloud [12/8396] Cloud mean volume density 78- 81 I4 cm-3 e_nCloud [7/5985] The 1{sigma} error in nCloud 83- 85 F3.1 Myr tff [0.3/10] Free-fall time 87- 89 F3.1 Myr e_tff [0.2/8] The 1{sigma} error in tff -------------------------------------------------------------------------------- Note (2): Code as follows: 1 = the earliest stage of massive star formation (Type II of Kawamura+, 2009, J/ApJS/184/1) 2 = the initial feedback from massive stars; 3 = a very late stage in which the original cloud has been mostly photoionized or dispersed, leaving only small fragments, similar to Type III clouds in the Kawamura+, (2009, J/ApJS/184/1) classification. -------------------------------------------------------------------------------- Byte-by-byte Description of file: table4.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 15 A15 --- ID WISE identifier (GLLL.lll+BB.bbb) (G1) 17- 23 F7.1 Msun Mdense [128/25706]?=-99.9 Aggregate mass of dense gas 25- 31 F7.1 Msun e_Mdense [51/10085]?=-99.9 Mdense 1{sigma} uncertainty 33- 37 F5.1 pc rdense [0.5/10]?=-99.9 Aggregate radius of dense gas 39- 43 F5.1 pc e_rdense [0.1/2]?=-99.9 rdense 1{sigma} uncertainty 45- 51 F7.3 --- DGMF [0.002/0.5]?=-99.9 Dense gas mass fraction 53- 59 F7.3 --- e_DGMF [0.001/0.3]?=-99.9 DGMF 1{sigma} uncertainty -------------------------------------------------------------------------------- Global note: Note (G1): Objects are <[ABB2014] WISE GLLL.lll+BB.bbb> in Simbad. History: From electronic version of the journal ================================================================================ (End) Prepared by [AAS], Emmanuelle Perret [CDS] 27-Jan-2017