Search Publications
Exploring Dust Extinction at the Edge of Reionization
Fynbo, Johan P. U.; Tanvir, Nial R.; Levan, Andrew J. +3 more
The brightness of gamma-ray burst (GRB) afterglows and their occurrence in young, blue galaxies make them excellent probes to study star-forming regions in the distant universe. We here elucidate dust extinction properties in the early universe through the analysis of the afterglows of all known z > 6 GRBs: GRB 090423, 080913, and 050904, at z …
Anatomy of a Post-starburst Minor Merger: A Multi-wavelength WFC3 Study of NGC 4150
Mutchler, Max; McCarthy, Patrick J.; Calzetti, Daniela +22 more
We present a spatially resolved near-UV/optical study, using the Wide Field Camera 3 (WFC3) on board the Hubble Space Telescope, of NGC 4150, a sub-L *, early-type galaxy (ETG) of around 6 × 109 M sun, which has been observed as part of the WFC3 Early-Release Science Programme. Previous work indicates that this gal…
Twelve and a Half Years of Observations of Centaurus a with the Rossi X-Ray Timing Explorer
Wilms, J.; Pottschmidt, K.; Kadler, M. +5 more
The Rossi X-ray Timing Explorer (RXTE) has observed the nearest radio galaxy, Centaurus A (Cen A), in 13 intervals from 1996 August to 2009 February over the 3-200 keV band. Spectra accumulated over the 13 intervals were well described with an absorbed power law and an iron line. Cutoff power laws and Compton reflection from cold matter did not pr…
Discovery of an Energetic 38.5 ms Pulsar Powering the Gamma-ray Source IGR J18490-0000/HESS J1849-000
Gotthelf, E. V.; Terrier, R.; Halpern, J. P. +1 more
We report the discovery of a 38.5 ms X-ray pulsar in observations of the soft γ-ray source IGR J18490-0000 with the Rossi X-ray Timing Explorer (RXTE). PSR J1849-0001 is spinning down rapidly with period derivative 1.42 × 10-14 s s-1, yielding a spin-down luminosity \dot{E} = 9.8 × 1036 erg s-1, characte…
Observing Evolution in the Supergranular Network Length Scale During Periods of Low Solar Activity
McIntosh, Scott W.; Ulrich, Roger K.; Leamon, Robert J. +2 more
We present the initial results of an observational study into the variation of the dominant length scale of quiet solar emission: supergranulation. The distribution of magnetic elements in the lanes that from the network affects, and reflects, the radiative energy in the plasma of the upper solar chromosphere and transition region at the magnetic …
Low-frequency Observations of Polarized Emission from Long-lived Non-thermal Radio Sources in the Solar Corona
Ramesh, R.; Kathiravan, C.; Narayanan, A. Satya
We report observations of circularly polarized emission from the solar corona at 77 MHz during the periods 2006 August 11-18, 2006 August 23-29, and 2007 May 16-22 in the minimum phase between the sunspot cycles 23 and 24. The observations were carried out with the east-west one-dimensional radio polarimeter at the Gauribidanur observatory located…
Evidence for Three Accreting Black Holes in a Galaxy at z ~ 1.35: A Snapshot of Recently Formed Black Hole Seeds?
Schawinski, Kevin; Natarajan, Priyamvada; Treister, Ezequiel +3 more
One of the key open questions in cosmology today pertains to understanding when, where, and how supermassive black holes form. While it is clear that mergers likely play a significant role in the growth cycles of black holes, the issue of how supermassive black holes form, and how galaxies grow around them, still needs to be addressed. Here, we pr…
Suzaku View of X-Ray Spectral Variability of the Radio Galaxy Centaurus A: Partial Covering Absorber, Reflector, and Possible Jet Component
Fukazawa, Yasushi; Ohno, Masanori; Yamazaki, Syoko +6 more
We observed a nearby radio galaxy, Centaurus A (Cen A), three times with Suzaku in 2009 and measured the wide-band X-ray spectral variability more accurately than previous measurements. The Cen A was in an active phase in 2009, and the flux became higher by a factor of 1.5-2.0 and the spectrum became harder than that in 2005. The Fe-K line intensi…
The Suzaku view of 3C 382
Ballo, L.; Reynolds, C. S.; Tombesi, F. +4 more
We present a long (116 ks) Suzaku observation of the broad-line radio galaxy (BLRG) 3C 382 acquired in 2007 April. A Swift BAT spectrum in 15-200 keV from the 58 month survey is also analyzed, together with an archival XMM-Newton EPIC exposure of 20 ks obtained one year after Suzaku. Our main result is the finding with Suzaku of a broad Fe K line …
Suzaku View of the Swift/BAT Active Galactic Nuclei. IV. Nature of Two Narrow-line Radio Galaxies (3C 403 and IC 5063)
Ueda, Yoshihiro; Terashima, Yuichi; Mushotzky, Richard F. +1 more
We report the results of Suzaku broadband X-ray observations of the two narrow-line radio galaxies, 3C 403 and IC 5063. Combined with the Swift/Burst Alert Telescope (BAT) spectra averaged for 58 months, we are able to accurately constrain their spectral properties over the 0.5-200 keV band. The spectra of both nuclei are well represented with an …