Search Publications
Reflection from the strong gravity regime in a lensed quasar at redshift z = 0.658
Miller, J. M.; Reis, R. C.; Walton, D. J. +1 more
The co-evolution of a supermassive black hole with its host galaxy through cosmic time is encoded in its spin. At z > 2, supermassive black holes are thought to grow mostly by merger-driven accretion leading to high spin. It is not known, however, whether below z ~ 1 these black holes continue to grow by coherent accretion or in a chaotic manne…
Probing cosmic rays in nearby giant molecular clouds with the Fermi Large Area Telescope
Aharonian, Felix; Yang, Rui-zhi; de Oña Wilhelmi, Emma
We report the results of our study of the energy spectra and absolute fluxes of cosmic rays (CRs) in the Local Galaxy based on a five-year γ-ray observation with the Fermi Large Area Telescope (LAT) of eight nearby giant molecular clouds (GMCs) belonging to the Gould Belt. The γ-ray signals obtained with high statistical significance allow the det…
Periodic and Aperiodic Variability in the Molecular Cloud ρ Ophiuchus
Plavchan, Peter; Parks, J. Robert; White, Russel J. +1 more
Presented are the results of a near-IR photometric survey of 1678 stars in the direction of the ρ Ophiuchus (ρ Oph) star forming region using data from the 2MASS Calibration Database. For each target in this sample, up to 1584 individual J-, H-, and Ks -band photometric measurements with a cadence of ~1 day are obtained over three obser…
Inflationary steps in the Planck data
Hu, Wayne; Miranda, Vinícius
We extend and improve the modeling and analysis of large-amplitude, sharp inflationary steps for second order corrections required by the precision of the Planck cosmic microwave background power spectrum and for arbitrary Dirac-Born-Infeld sound speed. With two parameters, the amplitude and frequency of the resulting oscillations, step models imp…
Bolometric and UV Light Curves of Core-collapse Supernovae
Brown, Peter J.; Pritchard, T. A.; Roming, P. W. A. +2 more
The Swift UV-Optical Telescope (UVOT) has been observing core-collapse supernovae (CCSNe) of all subtypes in the UV and optical since 2005. Here we present 50 CCSNe observed with the Swift UVOT, analyzing their UV properties and behavior. Where we have multiple UV detections in all three UV filters (λ c = 1928-2600 Å), we generate earl…
Type IIb Supernova SN 2011dh: Spectra and Photometry from the Ultraviolet to the Near-infrared
Foley, Ryan J.; Bieryla, Allyson; Berlind, Perry +26 more
We report spectroscopic and photometric observations of the Type IIb SN 2011dh obtained between 4 and 34 days after the estimated date of explosion (May 31.5 UT). The data cover a wide wavelength range from 2000 Å in the ultraviolet (UV) to 2.4 µm in the near-infrared (NIR). Optical spectra provide line profiles and velocity measurements of …
Stellar Metallicity of the Extended Disk and Distance of the Spiral Galaxy NGC 3621
Hosek, Matthew W., Jr.; Bresolin, Fabio; Kudritzki, Rolf-Peter +2 more
Low resolution (~4.5 Å) ESO VLT/FORS spectra of blue supergiant stars are analyzed to determine stellar metallicities (based on elements such as iron, titanium, and magnesium) in the extended disk of the spiral galaxy, NGC 3621. Mildly subsolar metallicity (-0.30 dex) is found for the outer objects beyond 7 kpc, independent of galactocentric radiu…
Wide-field Hubble Space Telescope Observations of the Globular Cluster System in NGC 1399
Maccarone, Thomas J.; Goudfrooij, Paul; Puzia, Thomas H. +3 more
We present a comprehensive high spatial resolution imaging study of globular clusters (GCs) in NGC 1399, the central giant elliptical cD galaxy in the Fornax galaxy cluster, conducted with the Advanced Camera for Surveys (ACS) aboard the Hubble Space Telescope (HST). Using a novel technique to construct drizzled point-spread function libraries for…
Star formation in the cluster CLG0218.3-0510 at z = 1.62 and its large-scale environment: the infrared perspective
Altieri, B.; Valtchanov, I.; Dickinson, M. +7 more
The galaxy cluster CLG0218.3-0510 at z = 1.62 is one of the most distant galaxy clusters known, with a rich multiwavelength data set that confirms a mature galaxy population already in place. Using very deep, wide-area (20 Mpc × 20 Mpc) imaging by Spitzer MIPS at 24 µm, in conjunction with Herschel five-band imaging from 100 to 500 µm,…
The Mice at play in the CALIFA survey. A case study of a gas-rich major merger between first passage and coalescence
Marino, Raffaella A.; Johnson, Benjamin D.; Gallazzi, Anna +43 more
We present optical integral field spectroscopy (IFS) observations of the Mice, a major merger between two massive (≳1011 M⊙) gas-rich spirals NGC 4676A and B, observed between first passage and final coalescence. The spectra provide stellar and gas kinematics, ionised gas properties, and stellar population diagnostics, over t…