分类： 天文学 >> 天文学 提交时间： 2023-02-19
Daniel Callanan
Steven N. Longmore
Cara Battersby
H. Perry Hatchfield
Daniel L. Walker
Jonathan Henshaw
Eric Keto
Ashley Barnes
Adam Ginsburg
Jens Kauffmann
Diederik Kruijssen
Xing Lu
Elisabeth A. C. Mills
Thushara Pillai
Qizhou Zhang
John Bally
Natalie Butterfield
Yanett A. Contreras
Luis C. Ho
Katharina Immer
摘要： We present an overview and data release of the spectral line component of the SMA Large Program, \textit{CMZoom}. \textit{CMZoom} observed $^{12}$CO(2-1), $^{13}$CO(2-1) and C$^{18}$O(2-1), three transitions of H$_{2}$CO, several transitions of CH$_{3}$OH, two transitions of OCS and single transitions of SiO and SO, within gas above a column density of N(H$_2$)$\ge 10^{23}$\,cm$^{-2}$ in the Central Molecular Zone (CMZ; inner few hundred pc of the Galaxy). We extract spectra from all compact 1.3\,mm \emph{CMZoom} continuum sources and fit line profiles to the spectra. We use the fit results from the H$_{2}$CO 3(0,3)-2(0,2) transition to determine the source kinematic properties. We find $\sim 90$\% of the total mass of \emph{CMZoom} sources have reliable kinematics. Only four compact continuum sources are formally self-gravitating. The remainder are consistent with being in hydrostatic equilibrium assuming that they are confined by the high external pressure in the CMZ. Based on the mass and density of virially bound sources, and assuming star formation occurs within one free-fall time with a star formation efficiency of $10\% - 75\%$, we place a lower limit on the future embedded star-formation rate of $0.008 - 0.06$\,M$_{\odot}$\,yr$^{-1}$. We find only two convincing proto-stellar outflows, ruling out a previously undetected population of very massive, actively accreting YSOs with strong outflows. Finally, despite having sufficient sensitivity and resolution to detect high-velocity compact clouds (HVCCs), which have been claimed as evidence for intermediate mass black holes interacting with molecular gas clouds, we find no such objects across the large survey area.
分类： 天文学 >> 天文学 提交时间： 2023-02-19
THE CASA TEAM
Ben Bean
Sanjay Bhatnagar
Sandra Castro
Jennifer Donovan Meyer
Bjorn Emonts
Enrique Garcia
Robert Garwood
Kumar Golap
Justo Gonzalez Villalba
Pamela Harris
Yohei Hayashi
Josh Hoskins
Mingyu Hsieh
Preshanth Jagannathan
Wataru Kawasaki
Aard Keimpema
Mark Kettenis
Jorge Lopez
Joshua Marvil
摘要： CASA, the Common Astronomy Software Applications, is the primary data processing software for the Atacama Large Millimeter/submillimeter Array (ALMA) and the Karl G. Jansky Very Large Array (VLA), and is frequently used also for other radio telescopes. The CASA software can handle data from single-dish, aperture-synthesis, and Very Long Baseline Interferometery (VLBI) telescopes. One of its core functionalities is to support the calibration and imaging pipelines for ALMA, VLA, VLA Sky Survey (VLASS), and the Nobeyama 45m telescope. This paper presents a high-level overview of the basic structure of the CASA software, as well as procedures for calibrating and imaging astronomical radio data in CASA. CASA is being developed by an international consortium of scientists and software engineers based at the National Radio Astronomical Observatory (NRAO), the European Southern Observatory (ESO), the National Astronomical Observatory of Japan (NAOJ), and the Joint Institute for VLBI European Research Infrastructure Consortium (JIV-ERIC), under the guidance of NRAO.
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