Research
o Spitzer IRAC Dark Field
§ The dark current for the near-IR camera on Spitzer is calibrated by observing a ~20 arcminute diameter field near the north ecliptic pole roughly every three weeks throughout the mission duration of Spitzer. The field is unique for its extreme depth, low background, high quality imaging, time-series information, and accompanying photometry including data taken with Palomar, MMT, Akari, KPNO, Chandra, and HST. This serendipitous survey contains the deepest mid-IR data taken to date. The science goals of acquiring this dataset are the study of high redshift galaxy clusters (z=1), characterizing high redshift galaxies (z > 6), compton thick AGN, the lowest mass brown dwarfs, population III Sne, the reddest objects in the universe from their 24 micron - r colors, and other interesting phenomenon, the study of which is uniquely suited to this field. As this is the only mid-IR dataset with time domain information on a 5+ year timeline, we are exploring the variable objects in the field, from stars to AGN
§ Krick, J.E. et al., 2009 ApJS, 185, 85
§ Krick, J.E. et al., 2009 ApJ, 700, 123
§ Krick, J.E. et al., 2009 AAS, 21344826
§ Krick, J.E. et al., 2008 ApJ, 686, 918
§ Krick, J.E. et al., 2008 ASPC 399 365
§ Krick, J.E. et al., 2007 AAS, 2101204
§ Surace, J.A. et al., 2007 AAS 2100205
o Intracluster Light
§ When counting up the mass in clusters of galaxies, the obvious sources of baryons are the galaxies themselves and the hot gas between the galaxies. There are also stars between the galaxies that are not bound to any particular galaxy but to the potential well of the cluster. These intracluster stars are a product of galaxy mergers and interactions between the galaxies and the cluster potential. The main goal in studying the intracluster light (ICL) is to use its total flux, color, and substructure to constrain models of galaxy evolution and galaxy interactions in clusters. Another product of the study of the ICL is a more complete census of the baryons in the universe. This project aims to study clusters with different masses and morphologies at a range of redshifts, to obtain the fraction of total light as well as the color of the ICL. This will allow us to test models of galaxy evolution and inform cosmological simulations.
§ J.E. Krick, and R.A. Bernstein, 2007, AJ, 134, 466
§ J.E. Krick, R.A. Bernstein, & K.A. Pimbblet 2006, AJ, 131, 168
§ January 2004 AAS poster (pdf)
§ IAU 195:Outskirts of Galaxy Clusters, March 2004, conference proceedings
o Cluster Soft Excess
§ The observed small-scale structure in the Galactic gas layer can lead to systematic residuals at optical depths greater than unity. This can lead to apparent emmision at soft X-ray energies, such as for EUVE, ROSAT, and XMM.
§ Bregman, J.N., Novicki, M.C., Krick, J.E, & Arabadjis, J.S. 2003, ApJ, 597