Nicholas Hunt-Walker
City University of New York - York College

REU program-Summer 2009
Research projects of other REU students
Univ. of Wisconsin - Madison
Madison, WI 53706

Email: nhuntwalker [at] gmail [dot] com

Research Picture


Background Information Research Objectives Methods About Me Links Credits

Background Information

What Emits Astrophysical X-rays?

Cosmic X-rays span 2 bands:
0.12 to 12 keV: Soft X-rays
12 to 120 keV: Hard X-rays
with super-soft X-rays being between 0.12 and 2.0 keV.

What emits these astrophysical x-rays? A variety of objects and processes, including but not limited to black hole accretion disks in active galactic nuclei; emission from supernova remnants; mass accretion due to Roche-lobe overflow in binary star systems that contain a white dwarf, neutron star, or black hole (called X-ray binares); and even simple main sequence stars. Whether we see them or not will depend upon how close they are to us, how sensitive our instruments are, and what intervening matter might be in the path of this light.

An artist's rendition of the binary star system Cygnus X-1, with a black hole accreting matter from a supergiant.
Source: Astronomy Picture of the Day: Black Hole Candidate Cygnus X-1
An X-ray (blue), optical(yellow), and radio(red) composite image of a Supernova Remnant.
Source: Astronomy Picture of the Day: SN 1006 Supernova Remnant
An artist's rendition of an active galactic nucleus, with the inset being an actual image from the Chandra X-ray Observatory
Source: Astronomy Picture of the Day: The Most Distant X-ray Jet
The Pleiades star cluster, as observed in the optical. It's an open cluster of fairly young, blue stars.
Source: Astronomy Picture of the Day: M45: The Pleiades Star Cluster

<<<<< Backward to X-Rays <<<<<

>>>>> Onward to the X-Ray Observatories >>>>>