Surveys of Clumps, Cores, and Condensations in Cygnus X: I. a New Catalog of ~0.1 pc Massive Dense Cores. (arXiv:1901.06475v1 [astro-ph.GA])
<a href="http://arxiv.org/find/astro-ph/1/au:+Cao_Y/0/1/0/all/0/1">Yue Cao</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Qiu_K/0/1/0/all/0/1">Keping Qiu</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Zhang_Q/0/1/0/all/0/1">Qizhou Zhang</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Wang_Y/0/1/0/all/0/1">Yuwei Wang</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Hu_B/0/1/0/all/0/1">Bo Hu</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Liu_J/0/1/0/all/0/1">Junhao Liu</a>
Using infrared to (sub)millimeter data from Spitzer, Herschel, the James
Clerk Maxwell Telescope, and the IRAM 30-m telescope, we conducted an unbiased
survey of the massive dense cores (MDCs) in the Cygnus X molecular cloud
complex, aimed at characterizing the physical conditions of high-mass star
formation (HMSF) at ~0.1 pc scales. We created 5 deg times 6 deg images of the
70-1200 um dust continuum, gas column density, and dust temperature of Cygnus
X. A spatial relation between the dense regions (Av > 15) and the developed HII
regions was found, indicating the impact of the latter on the global structures
of Cygnus X. With a 35-Msun mass threshold implied by HMSF signposts, we
identified 151 MDCs with sizes of ~0.1 pc, masses of 35-1762 Msun, and
temperatures of 8-35 K. Our MDC sample is statistically complete in Cygnus X
and is three times larger than that in Motte et al. (2007). The MDCs were
classified into IR-bright/IR-quiet ones based on their mid-infrared fluxes and
a large “IR-quiet” proportion (90%) was found in our sample. Two possible
scenarios were proposed to interpret this: accelerated HMSF and the
incapability of HMSF of the IR-quiet MDCs. We also found 26 starless MDCs by
their lack of compact emissions at 21-70 um wavelengths, of which the most
massive ones are probably the best candidates of initial HMSF sites in Cygnus
X.
Using infrared to (sub)millimeter data from Spitzer, Herschel, the James
Clerk Maxwell Telescope, and the IRAM 30-m telescope, we conducted an unbiased
survey of the massive dense cores (MDCs) in the Cygnus X molecular cloud
complex, aimed at characterizing the physical conditions of high-mass star
formation (HMSF) at ~0.1 pc scales. We created 5 deg times 6 deg images of the
70-1200 um dust continuum, gas column density, and dust temperature of Cygnus
X. A spatial relation between the dense regions (Av > 15) and the developed HII
regions was found, indicating the impact of the latter on the global structures
of Cygnus X. With a 35-Msun mass threshold implied by HMSF signposts, we
identified 151 MDCs with sizes of ~0.1 pc, masses of 35-1762 Msun, and
temperatures of 8-35 K. Our MDC sample is statistically complete in Cygnus X
and is three times larger than that in Motte et al. (2007). The MDCs were
classified into IR-bright/IR-quiet ones based on their mid-infrared fluxes and
a large “IR-quiet” proportion (90%) was found in our sample. Two possible
scenarios were proposed to interpret this: accelerated HMSF and the
incapability of HMSF of the IR-quiet MDCs. We also found 26 starless MDCs by
their lack of compact emissions at 21-70 um wavelengths, of which the most
massive ones are probably the best candidates of initial HMSF sites in Cygnus
X.
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