2006A&A...451..539S


Query : 2006A&A...451..539S

2006A&A...451..539S - Astronomy and Astrophysics, volume 451, 539-549 (2006/5-4)

A KOSMA 7 deg2 13CO 2-1 and 12CO 3-2 survey of the Perseus cloud. I. Structure analysis.

SUN K., KRAMER C., OSSENKOPF V., BENSCH F., STUTZKI J. and MILLER M.

Abstract (from CDS):

Characterizing the spatial and velocity structure of molecular clouds is a first step towards a better understanding of interstellar turbulence and its link to star formation. We present observations and structure analysis results for a large-scale (∼7.10deg2) 13CO J=2-1 and 12CO J=3-2 survey towards the nearby Perseus molecular cloud observed with the KOSMA 3m telescope. We study the spatial structure of line-integrated and velocity channel maps, measuring the Δ-variance as a function of size scale. We determine the spectral index β of the corresponding power spectrum and study its variation across the cloud and across the lines. We find that the spectra of all CO line-integrated maps of the whole complex show the same index, β≃3.1, for scales between about 0.2 and 3pc, independent of isotopomer and rotational transition. A complementary 2MASS map of optical extinction shows a noticeably smaller index of 2.6. In contrast to the overall region, the CO maps of individual subregions show a significant variation of β. The 12CO 3-2 data provide e.g. a spread of indices between 2.9 in L1455 and 3.5 in NGC1333. In general, active star forming regions show a larger power-law exponent. We find that the Δ-variance spectra of individual velocity channel maps are very sensitive to optical depth effects clearly indicating self-absorption in the densest regions. When studying the dependence of the channel-map spectra as a function of the velocity channel width, the expected systematic increase of the spectral index with channel width is only detected in the blue line wings. This could be explained by a filamentary, pillar-like structure which is left at low velocities while the overall molecular gas is swept up by a supernova shock wave.

Abstract Copyright:

Journal keyword(s): ISM: clouds - ISM: structure - ISM: individual objects: Perseus

Simbad objects: 12

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Number of rows : 12
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 NAME SMC G 00 52 38.0 -72 48 01   2.79 2.2     ~ 11178 1
2 LDN 1448 DNe 03 22.5 +30 35           ~ 516 0
3 LDN 1455 DNe 03 28 00.6480 +30 07 58.800           ~ 187 1
4 NGC 1333 OpC 03 29 11.3 +31 18 36           ~ 1454 1
5 Barnard 1 MoC 03 33 16.3 +31 07 51           ~ 325 0
6 NAME Perseus Cloud SFR 03 35.0 +31 13           ~ 1371 0
7 [DB2002b] G159.83-18.56 DNe 03 40.0 +31 58           ~ 11 0
8 Ass Per OB 2 As* 03 42.2 +33 26           ~ 339 0
9 IC 348 OpC 03 44 31.7 +32 09 32           ~ 1395 1
10 NAME [BM89] B5 DNe 03 47 38.3 +32 52 43           ~ 224 0
11 LDN 1471 DNe 03 48.0 +32 54           ~ 329 0
12 NAME Polaris Flare MoC 11 00 14.8 +86 10 52           ~ 193 1

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