2013ApJ...778..133L


C.D.S. - SIMBAD4 rel 1.7 - 2021.04.18CEST11:49:13

2013ApJ...778..133L - Astrophys. J., 778, 133 (2013/December-1)

Schmidt's conjecture and star formation in molecular clouds.

LADA C.J., LOMBARDI M., ROMAN-ZUNIGA C., FORBRICH J. and ALVES J.F.

Abstract (from CDS):

We investigate Schmidt's conjecture (i.e., that the star formation rate (SFR) scales in a power-law fashion with the gas density) for four well-studied local molecular clouds (giant molecular clouds, GMCs). Using the Bayesian methodology, we show that a local Schmidt scaling relation of the form Σ*(AK) = κAKβ (protostars/pc2) exists within (but not between) GMCs. Further, we find that the Schmidt scaling law does not by itself provide an adequate description of star formation activity in GMCs. Because the total number of protostars produced by a cloud is given by the product of Σ*(AK) and S'(> AK), the differential surface area distribution function, integrated over the entire cloud, the cloud's structure plays a fundamental role in setting the level of its star formation activity. For clouds with similar functional forms of Σ*(AK), observed differences in their total SFRs are primarily due to the differences in S'(> AK) between the clouds. The coupling of Σ*(AK) with the measured S'(> AK) in these clouds also produces a steep jump in the SFR and protostellar production above AK∼ 0.8 mag. Finally, we show that there is no global Schmidt law that relates the SFR and gas mass surface densities between GMCs. Consequently, the observed Kennicutt-Schmidt scaling relation for disk galaxies is likely an artifact of unresolved measurements of GMCs and not a result of any underlying physical law of star formation characterizing the molecular gas.

Abstract Copyright:

Journal keyword(s): galaxies: star formation - ISM: clouds - stars: formation

Simbad objects: 11

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Number of rows : 11

N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2021
#notes
1 NAME California Molecular Cloud MoC 04 10.0 +39 00           ~ 108 1
2 NAME Taurus Complex SFR 04 41.0 +25 52           ~ 3680 0
3 NAME LIC Cld 04 41 +31.           ~ 255 0
4 NAME Ori A MoC 05 38 -07.1           ~ 2757 0
5 NAME Ori B MoC 05 41 43.0 -01 54 44           ~ 1217 0
6 NAME ORI MOL CLOUD MoC 05 56 -01.8           ~ 899 1
7 NAME Rosette Molecular Cloud MoC 06 34.7 +04 02           ~ 233 0
8 NAME Ophiuchus Molecular Cloud SFR 16 28 06 -24 32.5           ~ 3156 1
9 NAME the Pipe Nebula DNe 17 30 -25.0           ~ 351 1
10 NAME Serpens Cloud SFR 18 29 49 +01 14.8           ~ 967 2
11 NAME Gould Belt PoG ~ ~           ~ 752 1

    Equat.    Gal    SGal    Ecl

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2021.04.18-11:49:13

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