Research Projects

Qizhou Zhang: Magnetic Fields and Massive Star Formation

Qizhou Zhang: Magnetic Fields and Massive Star Formation

December 1, 2015

Stars are assembled in molecular clouds when matters condense and collapse under the gravitational pull. Massive stars (M > 8 Msun) are found mostly in clusters together with lower mass stellar objects (Lada & Lada 2003). How parsec-scale, massive molecular clumps collapse and fragment to give rise to a cluster of stars has been one of the central questions in star formation in the past decade. Jeans mass, the characteristic mass of fragments, is 1Msun for typical physical conditions in (pre) cluster forming clumps (Zhang et al. 2009, 2015). This mass, after taking account the star… Read more about Qizhou Zhang: Magnetic Fields and Massive Star Formation

Martin Elvis: Asteroids

Martin Elvis: Asteroids

April 1, 2014

Asteroids have great interest: not only do they preserve information about the earliest times in the pre-Solar nebula, and as a result contain unique minerals, they are also hazards to the Earth (see Chelyabinks) and are the easiest objects to reach with spacecraft. As targets for human exploration, scientific discovery, retrieval to Earth-Moon space and sources of abundant resources both for space and on Earth, asteroids are worth paying attention to. I investigate all aspects of near-Earth asteroids related to hazards, expeditions and especially resources, i.e. asteroid mining. Several… Read more about Martin Elvis: Asteroids

Martin Elvis: Quasar Spectral Energy Distributions: Twisted Tori

Martin Elvis: Quasar Spectral Energy Distributions: Twisted Tori

April 1, 2014

For a long time we have known that our view of the centers of quasars is often blocked by optically thick dusty material - the “obscuring torus”. But to block a large solid angle requires a large height/radius ratio which is hard to achieve with cold matter. Andy Lawrence and I proposed that a thin torus that is twisted through large angles is a natural solution. I am investigating the spectral energy distributions (SEDs) of quasars in SDSS adding near-IR UKIDSS and mid-IR WISE data to see if the predictions of our model hold up.

The Three Forms of Radiation Pressure and the… Read more about Martin Elvis: Quasar Spectral Energy Distributions: Twisted Tori

Shep Doeleman: Imaging Black Holes with The Event Horizon Telescope

Shep Doeleman: Imaging Black Holes with The Event Horizon Telescope

November 19, 2013

Recent technical advances and observations have now demonstrated that the goal of making an image of a black hole is within reach. Using the technique of Very Long Baseline Interferometry (VLBI), in which widely separated radio dishes are linked together to form an Earth-sized array, our group has succeeded in confirming event horizon scale structures in two super massive black holes: Sagittarius A*, the 4 million solar mass black hole at the center of the Milky Way (Nature, 455, 78, '08), and M87, a 6 billion solar mass black hole in the giant elliptical galaxy Virgo A (Science, 338, 355… Read more about Shep Doeleman: Imaging Black Holes with The Event Horizon Telescope

Howard Smith: The Evolving Physical Processes in Interacting Galaxies Traced by Their Spectral Energy Distributions

Howard Smith: The Evolving Physical Processes in Interacting Galaxies Traced by Their Spectral Energy Distributions

November 6, 2013

The Evolving Physical Processes in Interacting Galaxies Traced by Their Spectral Energy Distributions

Mergers and interactions have profound effects on the evolution of galaxies and on the various physical processes associated with star formation and the fueling of active nuclei (AGN). There remains, however, an incomplete understanding of how interactions affect such processes or how important they are in controlling the appearance of today's universe.  Recent Harvard grad Lauranne Lanz for her thesis successfully completed a multi-band analyses (GALEX-Herschel) of set of 31… Read more about Howard Smith: The Evolving Physical Processes in Interacting Galaxies Traced by Their Spectral Energy Distributions