EPoS Contribution
EPoS Contribution
First results from the ALMA-IRDC survey: Properties and dynamics of dense cores in massive filaments

Ashley Barnes
AIfA, Bonn, DE
Infrared dark clouds (IRDCs) are potential hosts of the elusive early phases of high-mass star formation (HMSF). In this talk, I will discuss our recent initial results from the ALMA-IRDC survey investigating the fragmentation and chemical properties of a sample of 10 IRDCs, which have been highlighted as some of the best candidates to study HMSF within the Milky Way. To do so, we have obtained a set of large mosaics covering these IRDCs with ALMA at band 3 (at ~90GHz), which have a high spatial resolution (~0.05 pc), and high continuum (allowing ~Msun mass detections) and spectral line sensitivity (to detect extended N2H+ (1-0) line emission). The focus of this talk will be on the first paper in the ALMA-IRDC series. Here, we use these observations to identify and quantify the physical and dynamical properties of a number of potential sites of future high-mass star formation. This represents a key step in allowing us to test the predictions from high-mass star and cluster formation theories. I will end by introducing key ongoing and future projects in the series that aim at unveiling some of the more complex dynamical properties of these potential massive star-forming regions, and their links to larger scale cloud dynamics.
Caption: Main panel: A three colour image of the Galactic plane where several infrared dark clouds (IRDCs) can be seen as dark extinction features. In this image, red is 8 μm, green is 5.8 μm and blue is 4.5 μm emission from the Spitzer GLIMPSE survey. Labelled are three IRDCs that are investigated within this work: Clouds F, G and H (or G034.43+00.24, G034.77-00.55, G035.39-00.33). The panels show zoom-ins of these IRDCs for more detail. Inset for Cloud F: (first column) Three colour images from the Spitzer GLIMPSE survey. (second) The ALMA 3 mm dust continuum (without the primary beam correction), and (third) N2H+(1-0) integrated intensity maps. (fourth) Combined near- and mid-infrared extinction derived mass surface density maps. (fifth) Far-infrared Herschel derived column density, and (sixth) dust temperature maps. The yellow circles overlaid on each panel show the positions and sizes of 70μm emission point sources. The coloured contours overlaid on each panel show boundaries of all the “leaves” (or cores) identified using the dendrogram analysis on the dust continuum maps.
Collaborators:
G. Cosentino
J.C. Tan
P. Caselli
I. Jimenez-Serra
J.D. Henshaw
F. Fontani
J. E. Pineda
C.Y. Law
A. Avison
F. Bigiel
S. Feng
S. Kong
S.N. Longmore
L. Moser
R.J. Parker
A. Sanchez-Monge
K. Wang
Key publication

Suggested Session: Cores