2016A&A...591A..31L

Query : 2016A&A...591A..31L

2016A&A...591A..31L - Astronomy and Astrophysics, volume 591A, 31-31 (2016/7-1)

Formation of a protocluster: A virialized structure from gravoturbulent collapse. II. A two-dimensional analytical model for a rotating and accreting system.

LEE Y.-N. and HENNEBELLE P.

Abstract (from CDS):

Context. Most stars are born in the gaseous protocluster environment where the gas is reprocessed after the global collapse from the diffuse molecular cloud. The knowledge of this intermediate step gives more accurate constraints on star formation characteristics.
Aims. We demonstrate that a virialized globally supported structure, in which star formation happens, is formed out of a collapsing molecular cloud, and we derive a mapping from the parent cloud parameters to the protocluster to predict its properties with a view to confront analytical calculations with observations and simulations.
Methods. We decomposed the virial theorem into two dimensions to account for the rotation and the flattened geometry. Equilibrium was found by balancing rotation, turbulence, and self-gravity, while turbulence was maintained through accretion driving and it dissipates in one crossing time. We estimated the angular momentum and the accretion rate of the protocluster from the parent cloud properties.
Results. The two-dimensional virial model predicts the size and velocity dispersion given the mass of the protocluster and that of the parent cloud. The gaseous protoclusters lie on a sequence of equilibrium with the trend R∼M0.5 with limited variations, depending on the evolutionary stage, parent cloud, and parameters that are not well known, such as turbulence driving efficiency by accretion and turbulence anisotropy. The model reproduces observations and simulation results successfully.
Conclusions. The properties of protoclusters follow universal relations and they can be derived from that of the parent cloud. The gaseous protocluster is an important primary stage of stellar cluster formation, and should be taken into account when studying star formation. Using simple estimates to infer the peak position of the core mass function (CMF) we find a weak dependence on the cluster mass, suggesting that the physical conditions inside protoclusters may contribute to set a CMF, and by extension an initial mass function (IMF), that appears to be independent of the environment.

Abstract Copyright: © ESO, 2016

Journal keyword(s): ISM: kinematics and dynamics - turbulence - ISM: structure - open clusters and associations: general - stars: protostars

Simbad objects: 1

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Number of rows : 1
N Identifier Otype ICRS (J2000)
RA 		ICRS (J2000)
DEC 		Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2024 		#notes
1 AGAL G028.344+00.061 cor 18 42 50.45 -04 03 17.7           ~ 86 0

Query : 2016A&A...591A..31L

Basic data :
AGAL G028.344+00.061 -- Dense Core
Origin of the objects types :

(Ref) Object type as listed in the reference "Ref"
(acronym) Object type linked to the acronym according to the original reference
() Anterior to 2007, before we can link the objet type to a reference, or given by the CDS team in some particular cases

Other object types: 		smm (AGAL,JCMTLSP,...), mm (2006ApJ,BGPS,...), cor (2014ApJ), DNe ([BT2009],[VVH2014]), Cld (MSXDC,[PWC2006]), Y*O (2018MNRAS), MoC (2017ApJ), Mas (2016ApJ)
Syntax of coordinates is : "ra dec (wtype) [error ellipse] quality bibcode" :
  • ra dec : right ascension and declination (unit and frame defined according to your Output Options)
    Grey values are increasing the original precision due to the computation of frame transformations
  • (wtype) : wavelength class for the origin of the coordinates (Rad, mm, IR, Optical, UV, Xray, Gam)
  • [error ellipse] : measurement uncertainty, on (ra,dec) if the positional angle is 90 degrees, on (majaxis,minaxis) otherwise (in mas at defined epoch in the original catalogue),
    position angle (in degrees North celestial pole to East)
  • quality : flag of quality
    • E ≥ 10"
    • D : 1-10" (and some old data)
    • C : 0.1-1"
    • B : 0.01-0.1" + 2MASS, Tyc
    • A : VLBI, Hipparcos
  • bibcode : bibcode of the coordinates reference
ICRS coord. (ep=J2000) : 		18 42 50.45 -04 03 17.7 (Radio) [ ] C 2017ApJ...834..193K
Syntax of coordinates is : "ra dec (wtype) [error ellipse] quality bibcode" :
  • ra dec : right ascension and declination (unit and frame defined according to your Output Options)
    Grey values are increasing the original precision due to the computation of frame transformations
  • (wtype) : wavelength class for the origin of the coordinates (Rad, mm, IR, Optical, UV, Xray, Gam)
  • [error ellipse] : measurement uncertainty, on (ra,dec) if the positional angle is 90 degrees, on (majaxis,minaxis) otherwise (in mas at defined epoch in the original catalogue),
    position angle (in degrees North celestial pole to East)
  • quality : flag of quality
    • E ≥ 10"
    • D : 1-10" (and some old data)
    • C : 0.1-1"
    • B : 0.01-0.1" + 2MASS, Tyc
    • A : VLBI, Hipparcos
  • bibcode : bibcode of the coordinates reference
FK4 coord. (ep=B1950 eq=1950) : 		18 40 11.98 -04 06 18.3 [ ]
Syntax of coordinates is : "ra dec (wtype) [error ellipse] quality bibcode" :
  • ra dec : right ascension and declination (unit and frame defined according to your Output Options)
    Grey values are increasing the original precision due to the computation of frame transformations
  • (wtype) : wavelength class for the origin of the coordinates (Rad, mm, IR, Optical, UV, Xray, Gam)
  • [error ellipse] : measurement uncertainty, on (ra,dec) if the positional angle is 90 degrees, on (majaxis,minaxis) otherwise (in mas at defined epoch in the original catalogue),
    position angle (in degrees North celestial pole to East)
  • quality : flag of quality
    • E ≥ 10"
    • D : 1-10" (and some old data)
    • C : 0.1-1"
    • B : 0.01-0.1" + 2MASS, Tyc
    • A : VLBI, Hipparcos
  • bibcode : bibcode of the coordinates reference
Gal coord. (ep=J2000) : 		028.34386 +00.06016 [ ]
Syntax of Velocity of Local System is : "VSLR Vmin Vmax [error] (wavelength) bibcode"
  • VLSR : central velocity (km/s)
  • Vmin : minimum of the velocity range (km/s)
  • Vmax : maximum of the velocity range (km/s)
  • [error] : velocity resolution (km/s)
  • (wavelength) : wavelength range of the measurement : Rad, mm, IR, Opt, UV, Xray, Gam or  '∼'(unknown)
  • bibcode : bibcode of the origin of the velocity
VLSR : 		77.87 77.54 78.20 [1] (Rad) 2016ApJ...822...59S
Syntax of angular size is : "maj-axis min-axis angle (wtype) quality bibcode"
  • maj-axis : major axis size (arc minutes)
  • min-axis : minor axis size (arc minutes)
  • angle : orientation angle (in degrees)
  • (wtype) : wavelength class for the origin of the angular size (Rad, mm, IR, Opt, UV, Xray, Gam)
  • quality : flag of quality of the angular size values ( A=best quality -> E=worst quality, {� } =unknown quality)
  • bibcode : bibcode of the angular size reference
Angular size (arcmin): 		0.73 0.50 78 (smm) D 2014A&A...568A..41U
SIMBAD within arcmin
', {sourceSize:12, color:'#30a090'})); aladin.on('objectClicked', function(object) { var objName=object.data.MAIN_ID; aladin.showPopup(object.ra,object.dec,'',''+ objName+''); });" title="Show Simbad objects"> Overlay Simbad points in this preview
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Hierarchy : number of linked objects
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: 1
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%This number is the number of distinct objets linked, by using this button, you will obtain all links (may be more than one) from that object to his children

: 8 		: 24 Display criteria :

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Identifiers (15) :
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AGAL G028.344+00.061 JCMTSF J184250.6-040314 [CFR2000] G028.34+0.06 P1 [RJS2006] MSXDC G028.37+00.07 MM4
BGPS G028.344+00.058 JPS G028.344+00.060 [ERG2015] 4672 [SSS2011] BGPS G28.345+0.058
JCMTLSP J184250.5-040317 MSXDC G028.37+0.07 a [MPT2015] G028.344+00.060 [VVH2014] IRDC G028.34-3
JCMTSE J184250.6-040314 [BT2009] C2 [PWC2006] NH3 G28.34+0.06 P1

References (86 between 1850 and 2024) (Total 86)
Simbad bibliographic survey began in 1850 for stars (at least bright stars) and in 1983 for all other objects (outside the solar system).
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velocities : 3    distance : 1   

   

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herschel : 4   

   

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