Dr. Jon Christian Mauerhan

Division of Astronomy and Astrophysics
Department of Physics & Astronomy
430 Portola Plaza
Box 951547
University of California, Los Angeles
Los Angeles, CA 90095-1547


Email: mauerhan@ipac.caltech.edu

Advisor: Professor Mark Morris
I have graduated, and moved to NASA Infrared Processing and Analysis Center (IPAC) at Caltech. I will have an updated site soon.

Education

Ph.D. Astronomy & Astrophysics, UCLA, 2008
M. Sc. Astronomy & Astrophysics, UCLA, 2004
B. Sc. Physics, UCSC, 2001

Research Interests

Massive Stellar X-Ray Sources in the Galactic Center

The center of our Milky Way Galaxy is host to an abundance of high-energy phenomena, much of which is driven by the recent formation, evolution, and death of blue supergiant stars having masses up to 150 times that of the sun. These stars have a profound influence on the Galactic center environment; they flood the region with intense UV radiation, impart mechanical energy and chemical enrichment to the interstellar medium through their supersonic winds and explosive death as supernovae explosions, and enter stellar afterlife as neutron stars and black holes. Blue supergiants can also be sources of high-energy X-rays. If they are members of a tight binary system, hard X-rays can be produced at the shocked interface of the two stars' opposing supersonic winds, where temperatures can reach tens of millions of degrees. In some single massive stars, magentic chanelling of the supersonic wind can induce microshocks, which will also produce hard X-rays. The focus of my disseration is a hunt for these rare objects by cross-correlating near-infrared and X-ray star catalogs to produce a sample of candidates, followed by near-infrared spectroscopy to characterize the stellar counterparts. The X-ray sample is produced from observations made by NASA's Chandra X-ray Observatory, which has now detected nearly 10,000 high-energy point sources toward the Galactic center (inner 2 by 0.8 degrees of the Milky Way).

Here's a link to a publication of some initial discoveries. Many more will soon follow.


Sagittarius A* - A Supermassive Black Hole at our Galaxy's Center with the Mass of 4,000,000 Suns



Using the Millimeter Interferometer Array at Owens Valley Radio Observatory (OVRO), I'm working on the 3-mm radio detection of intra-day variability of the compact radio source Sagittarius A*, an object associated with the ~4 million solar mass black hole at the center of our Milky Way Galaxy. The radio energy is thought to arise from the synchrotron radiation of electrons in the magnetized accretion flow onto the black hole. Detecting and characterizing time variations in radio intensity from this source will give information about the manner in which this exotic object consumes matter and grows as well as give insight into the radiation physics, structure and dynamics of gaseous flows in extreme gravity environments.

Click here for a to read the paper published in The Astrophysical Journal Letters

Besides Science


I play drums and study tabla