The Cygnus Allscale Survey of Chemistry and Dynamical Environments: CASCADE: Overview and first results toward DR20 from the Max Planck IRAM Observatory program (MIOP)

Abstract

Context: While star formation on large molecular cloud scales and on small core and disk scales has been investigated intensely over the past decades, the connection of the large-scale interstellar material with the densest small-scale cores has been a largely neglected field. Methods: Using NOEMA and the IRAM 30\,m telescope, we mapped large areas (640\,arcmin${}^2$) of the archetypical star formation complex Cygnus X at 3.6\,mm wavelengths in line and continuum emission. Results: The scope and outline of The Cygnus Allscale Survey of Chemistry and Dynamical Environments (CASCADE) is presented. We then focus on the first observed subregion in Cygnus X, namely the DR20 star formation site, which comprises sources in a range of evolutionary stages from cold pristine gas clumps to more evolved ultracompact H{\sc ii} regions. The data covering cloud to cores scales at a linear spatial resolution of $<5000$\,au reveal several kinematic cloud components that are likely part of several large-scale flows onto the central cores. The temperature structure of the region is investigated by means of the HCN/HNC intensity ratio and compared to dust-derived temperatures. We find that the deuterated DCO${}^{+}$ emission is almost exclusively located toward regions at low temperatures below 20\,K. Investigating the slopes of spatial power spectra of dense gas tracer intensity distributions (HCO${}^{+}$, H${}^{13}$CO${}^{+}$, and N${}_2$H${}^{+}$), we find comparatively flat slopes between $-2.9$ and $-2.6$, consistent with high Mach numbers and/or active star formation in DR20.

18 pages, 16 figures, accepted to A&A, also available at https://www2.mpia-hd.mpg.de/homes/beuther/papers.html

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Cited by in corpus (4)

• Data Combination: Interferometry and Single-dish Imaging in Radio Astronomy
• A global view on star formation: The GLOSTAR Galactic plane survey VIII. Formaldehyde absorption in Cygnus~X
• Variations of the HCO${}^{+}$, HCN, HNC, N${}_2$H${}^{+}$ and NH${}_3$ deuterium fractionation in high-mass star-forming regions
• The Cygnus Allscale Survey of Chemistry and Dynamical Environments: CASCADE. II. A detailed kinematic analysis of the DR21 Main outflow