MUNA Lunch Talk:

Viviana Rosero

New Mexico Tech

VLA Observations in Early Massive Star Formation Regions: A Search for Jets

November 10

12:10PM, Room 230, NRAO, Edgemont Road

Abstract:

Molecular outflows appear to be an ubiquitous phenomena among stars of all masses. However, to date only a handful of sources with disks and collimated jets have been detected in young massive objects (YMOs). It is not clear if the lack of detections are due to intrinsic properties of YMOs or due to observational disadvantages. We have performed a survey of YMOs with unprecedented sensitivity, using the Jansky VLA to achieve ~3-10 microJy RMS in C and K-band images (about 10-100 times more sensitive than previous efforts). The sample is composed of the earliest stages of massive star formation: hot molecular cores and infrared dark cloud cores. Moreover, all the sources show signatures of massive star formation such as methanol and water masers and outflow phenomena. This study provides a sample of jet candidates which is a valuable basis for a follow up search for associated disks. In this talk, I present preliminary results of the survey. We have a high detection rate of weak radio continuum emission from the YMOs in our sample, most of which were previously undetected. We have measured their spectral behavior and we are in the process of investigating their physical nature. In addition to the jet scenario, we are analyzing which other processes could be producing the radio emission; some of the detections appear to be from non-thermal emission, and others could be associated with ultra-compact HII regions.