• Home   /  
  • Archive by category "1"

Apj Submission Cover Letter

Stars are born from dense cores in molecular clouds. Observationally, it is crucial to capture the formation of cores in order to understand the necessary conditions and rate of the star formation process. The Atacama Large Millimeter/submillimeter Array (ALMA) is extremely powerful for identifying dense gas structures, including cores, at millimeter wavelengths via their dust continuum emission. Here, we use ALMA to carry out a survey of dense gas and cores in the central region of the massive (∼10 5M) infrared dark cloud (IRDC) G28.37+0.07. The observation consists of a mosaic of 86 pointings of the 12 m array and produces an unprecedented view of the densest structures of this IRDC. In this first Letter about this data set, we focus on a comparison between the 1.3 mm continuum emission and a mid-infrared (MIR) extinction map of the IRDC. This allows estimation of the “dense gas” detection probability function (DPF), i.e., as a function of the local mass surface density, Σ, for various choices of thresholds of millimeter continuum emission to define “dense gas.” We then estimate the dense gas mass fraction, fdg, in the central region of the IRDC and, via extrapolation with the DPF and the known Σ probability distribution function, to the larger-scale surrounding regions, finding values of about 5% to 15% for the fiducial choice of threshold. We argue that this observed dense gas is a good tracer of the protostellar core population and, in this context, estimate a star formation efficiency per free-fall time in the central IRDC region of ϵff ∼ 10%, with approximately a factor of two systematic uncertainties.


American Astronomical Society


To ensure proper functionality of this site, both JavaScript and Cookies must be enabled. If you are a first-time user, please read our author or reviewer instructions before logging in. Please note: All Login Names and Passwords are case sensitive.

Please Note: The EJ Press system does not use IOP login or passwords. Please send our office, journals.manager@aas.org, a message asking for your login information, or alternatively you can register as a new user.
Please submit all new and revised manuscripts through the new consolidated site, aas.msubmit.net, the ApJ site is now closed for submissions.

New Users: Register Here.Unknown/Forgotten password?


One thought on “Apj Submission Cover Letter

Leave a comment

L'indirizzo email non verrĂ  pubblicato. I campi obbligatori sono contrassegnati *