research and publications

Full list of publications on ADS and astro-ph.

Chandra image of the 9 square degree NDWFS field in Boötes

Active galactic nuclei and galaxy evolution
Much of my research focuses on studying large populations of active galactic nuclei (AGN) from multiwavelength surveys including wide-field Boötes data set. My work aims to explore the links between the fueling of black hole growth and the evolution of host galaxies and large-scale structures.

For an extensive review of AGN and galaxy evolution research motivated by the workshop in Durham on What Drives the Growth of Black Holes?, see our review article (Alexander & Hickox 2012) to appear in New Astronomy Reviews.

For a brief overview of this field geared toward a more general audience, see Supermassive Black Holes and the Growth of Galaxies, which appeared in the UK magazine The Astronomer in March/April 2011.

Recent journal articles:

  • "No submillimetre signature of suppressed star formation amongst X-ray luminous AGNs", C. M. Harrison, et al., 2012, ApJ Letters, 760, 15 (arXiv:1209.3016)

  • "GOODS-Herschel: radio-excess signature of hidden AGN activity in distant star-forming galaxies", A. Del Moro et al., 2012, A&A 459, 59 (arXiv:1210.2521)

  • "High-Velocity Outflows Without AGN Feedback: Eddington-Limited Star Formation in Compact Massive Galaxies", Diamond-Stanic, A.M. et al., 2012, ApJ Letters, 755, 26 (arXiv:1205.2368)

  • "Energetic galaxy-wide outflows in high-redshift ultra-luminous infrared galaxies hosting AGN activity", Harrison, C.M. et al., 2012, MNRAS, 426, 1073 (arXiv:1205.1801)

  • "The clustering of H-alpha emitters at z=2.23 from HiZELS", Geach, J. E., Sobral, D., Hickox, R. C. et al., 2012, MNRAS, 426, 679 (arXiv:1206.4052)

  • "Contribution of the accretion disk, hot corona, and obscuring torus to the luminosity of Seyfert galaxies: INTEGRAL and Spitzer observations", S. Sazonov et al., 2012, ApJ, 757, 181 (arXiv:1208.1612)

  • "The hidden "AGN main sequence": Evidence for a universal black hole accretion to star formation rate ratio since z~2 producing a M_BH-M* relation", Mullaney, J.R. et al., 2012, ApJ Letters, 753, 30 (arXiv:1204.2824)

  • "The Chandra X-ray Point Source Catalog in the DEEP2 Galaxy Redshift Survey Fields", A.D. Goulding et al., 2012, ApJS, 202, 6 (arxiv:1206.6884)

  • "Deep Silicate absorption features in Compton-thick AGN predominantly arise due to dust in the host galaxy", Goulding, A.D. et al., 2012, ApJ, 755, 5 (arXiv:1205.1800)

  • "The XMM Cluster Survey: The interplay between the brightest cluster galaxy and the intra-cluster medium via AGN feedback", Stott, J.P., Hickox, R.C., et al., 2012, MNRAS, 422, 2213 (arXiv:1202.3787)

  • "What Drives the Growth of Black Holes?", Alexander, D. M. & Hickox, R. C., 2012, New Astronomy Reviews in press (arXiv:1112.1949)

  • "The LABOCA Survey of the Extended Chandra Deep Field South: Clustering of submillimetre galaxies", R.C. Hickox et al. 2012, MNRAS, 421, 284 (arXiv:1112.0321)

  • "The galaxy optical luminosity function from the AGN and Galaxy Evolution Survey (AGES)", Cool, R., et al. 2012, ApJ, 748, 10 (arXiv:1201.2954)

  • "The evolution of AGN across cosmic time: what is downsizing?", N. Fanidakis et al. 2012, MNRAS, 419, 2797 (arXiv:1011.5222)

  • "GOODS-Herschel: The far-infrared view of star formation in AGN host galaxies since z~3", J. Mullaney et al. 2012, MNRAS, 419, 95 (arXiv:1106.4284)

  • "A candidate dual AGN at z=1.75", R.S. Barrows et al. 2012, ApJ, 744, 7 (arXiv:1109.3469)

  • "Constraining halo occupation properties of X-ray AGNs using clustering of Chandra sources in the Bootes survey region", S. Starikova et al. 2011, ApJ, 741, 15 (arXiv:1010.1577)

  • "X-ray spectral constraints for z~2 massive galaxies: The identification of reflection-dominated active galactic nuclei", D. Alexander et al. 2011, ApJ, 738, 44 (arXiv:1106.1443)

  • "Defining the intrinsic AGN infrared SED and measuring its contribution to the infrared output of composite galaxies", J.R. Mullaney et al. 2011, MNRAS, 414, 1082 (arXiv:1102.1425)

  • "X-ray emission from two infrared-selected galaxy clusters at z > 1.4 in the IRAC Shallow Cluster Survey", M. Brodwin et al. 2011, ApJ, 732, 33 (arXiv:1012.0581)

  • "Clustering of obscured and unobscured quasars in the Bootes field: Placing rapidly growing black holes in the cosmic web", R.C. Hickox et al. 2011, ApJ, 731, 117 (arXiv:1102.4850)

  • "Searching for Compton-thick active galactic nuclei at z~0.1", A.D. Goulding et al. 2011, MNRAS, 411, 1231-1244 (arXiv:1009.4929)

  • "The mid-IR and X-ray selected QSO luminosity function", R.J. Assef et al. 2011, ApJ, 728, 56 (arXiv:1001.4529)

  • "Constraining the outburst properties of the SMBH in Fornax A through X-ray, infrared, and radio observations", L. Lanz et al. 2010, ApJ, 721, 1702-1713, (arXiv:1008.1545)

  • "Low resolution spectral templates for AGNs and galaxies from 0.03-30 microns", R.J. Assef et al. 2010, ApJ, 713, 970-985 (arXiv:0909.3849)

  • "Active galactic nuclei and the truncation of star formation in K+A galaxies", M.J.I. Brown et al. 2009, ApJ, 703, 150-158 (arXiv:0907.3185)

Simple schematic of galaxy and AGN evolution (Hickox et al.~(2009)

  • "Black holes through cosmic time: Exploring the distant X-ray Universe with extragalactic Chandra surveys", R.C. Hickox et al. 2009, Chandra Newsletter cover article, Winter 2009 (arXiv:0904.3543)

  • "The star formation and nuclear accretion histories of normal galaxies in the AGES survey", C.R. Watson et al. 2009, ApJ, 696, 2206-2219 (arXiv:0903.2219)

  • "Host galaxies, clustering, Eddington ratios, and evolution of radio-, X-ray-, and infrared-selected AGNs", R.C. Hickox et al. 2009, ApJ, 696, 891-919 (arXiv:0901.4121)

  • "Are most low-luminosity AGN really obscured?", P.F. Hopkins, R.C. Hickox, E. Quataert & L. Hernquist 2009, MNRAS, 398, 333-349 (arXiv:0901.2936)

  • A large population of mid-infrared selected, obscured active galaxies in the Boötes field", R.C, Hickox et al. 2007, ApJ, 671, 1365-1387 (arXiv:0708.3678)

cosmic X-ray background
We have performed the absolute measurement of intensity of the cosmic X-ray background that has not been resolved into point sources by the extremely deep (1 and 2 million second exposure) Chandra Deep Fields. This can constrain a putative population of unresolved X-ray emitting galaxies, as well as put limits on diffuse emission such as the warm-hot intergalactic medium (WHIM) and decay of sterile neutrino dark matter.

  • "Can Chandra resolve the remaining cosmic X-ray background?", R.C. Hickox & M. Markevitch 2007, ApJ, 671, 1523-1531 (arXiv:0706.3089)

  • "Resolving the unresolved cosmic X-ray background in the Chandra Deep Fields", R.C. Hickox & M. Markevitch 2007, ApJ, 661, 117L-121L (astro-ph/0702556)

  • "Limits on the radiative decay of sterile neutrino dark matter from the unresolved cosmic and soft X-ray backgrounds", K. Abazajian et al. 2007, Phys. Rev. D, 75, 063511 (astro-ph/0611144)

  • "Absolute measurement of the unresolved X-ray background in the 0.5-8 keV band with Chandra", R.C. Hickox & M. Markevitch 2006, ApJ, 645, 95-114 (astro-ph/0512542)

X-ray pulsars
I am interested in the structure and emission properties of accretion onto X-ray pulsars, especially in systems such as Her X-1, SMC X-1, and LMC X-4 that show evidence for warped, precessing accretion disks. In these systems, reprocessing of the pulsed hard X-ray beam by the inner edge of the disk can allow us to explore the geometry of accretion near the magnetosphere.

  • "Ionized reflection spectra from accretion disks illuminated by X-ray pulsars", D. R. Ballantyne, J. D. Purvis, R. G. Strausbaugh, and R. C. Hickox, 2012, ApJL, 747, 35 (arXiv:1202.2311)

  • "Suzaku X-ray spectra and pulse profile variations during the superorbital cycle of LMC X-4", L.-W. Hung, R.C. Hickox, B.S. Boroson & S.D. Vrtilek 2010, ApJ, 720, 1202-1214 (arXiv:1007.3280)

  • "Pulse-phase spectroscopy of SMC X-1 with Chandra and XMM-Newton: reprocessing by a precessing disk?", R.C. Hickox & S.D. Vrtilek 2005, ApJ, 633, 1064-1075 (astro-ph/0506438)

  • "Origin of the soft excess in X-ray pulsars", R.C. Hickox, R. Narayan, & T. Kallman 2004, ApJ, 614, 881-896 (astro-ph/0407115)

  • "Phase variation in the pulse profile of SMC X-1", J. Neilsen, R.C. Hickox, & S.D. Vrtilek 2004, ApJ Letters, 616, L135-L138 (astro-ph/0410495)



Ryan C. Hickox
Department of Physics & Astronomy
Dartmouth College
Hanover, NH 03755

Office: 241 Wilder Laboratory
Phone: +1 (603) 646-2962
Email: Ryan.C.Hickox@dartmouth.edu

Last Updated: 2 January 2013
Banner Image: courtesy of Chandra X-ray Center