Studies of the interstellar medium (ISM) in other galaxies and its interface with local star forming regions are the central themes of the studies being performed by our group.

A brief description follows below of several projects that are underway,

including the group members involved and telescopes utilized.


CO Survey of Nearby Galaxies

Jin, Jennifer, Sarah, Nick, Rob, Tsuyoshi, Nario, Fumi, Momo, Masayuki, Misty

CARMA, Nobeyama 45-meter, VLA, Spitzer, GALEX, Herschel

We are exploring the emerging picture of ISM evolution, namely one driven by the global dynamics of galaxies instead of the popular scenario in which evolution is driven by feedback. By sampling a full range of dynamical environments (strong/weak spiral arms and bars) in 21 nearby spiral galaxies with CARMA, we will be able to identify individual giant molecular clouds (GMCs), while observations with the Nobeyama 45-meter telescope enable the study of extended CO emission. From the distribution of the GMCs, we can probe their formation and evolution within the context of galactic dynamics. From the environments of the GMCs, we can also obtain evidence pertaining to the triggering of star formation.

A full complement of data is available on the galaxies in this sample, including VLA, Spitzer, GALEX, and Herschel data, which are necessary to correlate the gas and star formation properties of the galaxies in our survey. The sensitivity and resolution of this project is 2-3 times higher than the previous BIMA-SONG survey; we are able to detect typical GMCs over entire galactic disks and resolve the scale at which star formation laws (e.g. Schmidt law) start to break down.

NH3 and H20 Survey of Extended Green Objects

Jin, Sarah, Fumi, Claudia, Momo, Masayuki

Nobeyama 45-meter

Studying high mass star formation is limited by the ability to identify massive young stellar objects (MYSOs) which will eventually become O- or early B-type stars. The environments of these objects have not yet been destroyed by feedback and are thought to be preserved. Recent Spitzer surveys provide the opportunity to attain the least source confusion to date of extended 4.5μm sources (or extended green objects, EGOs, called “green” as a result of their detection in the 4.5μm Spitzer band). As neither hyper-compact nor ultra-compact HII regions are observed to be associated with most EGOs, these objects are likely to be at a very early stage of high mass star formation. Observing these systems in NH3, and searching for H20 maser emission, provides information about the physical

A Catalog of Molecular Clouds in the Milky Way Galaxy

Jin, Matthew

BUFCRAO (FCRAO 14-meter)

We have created a complete catalog of molecular clouds in the Milky Way Galaxy. This is an extension of our previous study which used a preliminary data set from The Boston University Five College Radio Astronomy Observatory Galactic Ring Survey (BUFCRAO GRS). This work is of the complete data set from this GRS. The data covers the inner part of the northern Galactic disk between galactic longitudes 15 to 56 degrees, galactic latitudes -1.1 to 1.1 degrees, and the entire Galactic velocities. We used the standard cloud identification method. This method searches the data cube for a peak in temperature above a specified value,

parameters of these objects and the environments (i.e. the parent molecular cloud) where they were formed. These observations provide a direct measure of the objects’ velocities, temperatures, and densities, and from these we can estimate core/clump masses, which may then be compared to MYSO candidates selected using other methods to confirm that EGOs are in fact MYSOs.

Stratospheric Research Program at Stony Brook

Jin, James, Tom

Spectrometers at CSO and Scott Base, Antarctica

As part of the the Network for Detection of Stratospheric Change, Stony Brook operates two ground-based millimeter-wave (278 GHz) spectrometers monitoring stratospheric ClO, the compound most directly involved in the depletion of the ozone layer. One instrument is located at the Caltech Submillimeter Observatory on Mauna Kea in Hawaii, and the other at Scott Base, New Zealand's main research station in Antarctica. At left is the column density of CIO over Scott Base, Antarctica, during the 1996-2006 ozone holes. See the website for this project for more details.

Modelling project with Joern

Building the Stony Brook Radio Interferometer

Jin, Dan, lab students

Stony Brook Radio Interferometer

As a laboratory exercise, Jin and his advanced laboratory students are building Stony Brook University’s first radio interferometer. As updates occur, they will be posted here. Until funding increases, the demand will likely not exist for a transporter like the one shown on the left.

and then searches around that peak in all directions until the extents of the cloud are found. This method is iterated until all clouds are found. We prefer this method over other methods, because of its simplicity. The properties of our molecular clouds are very similar to those based on a more evolved method.