Search Publications
Simultaneous IRIS and Hinode/EIS Observations and Modelling of the 2014 October 27 X2.0 Class Flare
Mason, H. E.; Golub, L.; Del Zanna, G. +5 more
We present a study of the X2-class flare which occurred on 2014 October 27 and was observed with the Interface Region Imaging Spectrograph (IRIS) and the EUV Imaging Spectrometer (EIS) on board the Hinode satellite. Thanks to the high cadence and spatial resolution of the IRIS and EIS instruments, we are able to compare simultaneous observations o…
The Interaction of the Fermi Bubbles with the Milky Way’s Hot Gas Halo
Bregman, Joel N.; Miller, Matthew J.
The Fermi bubbles are two lobes filled with non-thermal particles that emit gamma rays, extend ≈ 10 {{kpc}} vertically from the Galactic center, and formed from either nuclear star formation or accretion activity on Sgr A*. Simulations predict a range of shock strengths as the bubbles expand into the surrounding hot gas halo ({T}{halo}≈…
Mid-infrared luminous quasars in the GOODS-Herschel fields: a large population of heavily obscured, Compton-thick quasars at z ≈ 2
Daddi, E.; Elbaz, D.; Alexander, D. M. +10 more
We present the infrared (IR) and X-ray properties of a sample of 33 mid-IR luminous quasars (νL6 µm ≥ 6 × 1044 erg s-1) at redshift z ≈ 1-3, identified through detailed spectral energy distribution analyses of distant star-forming galaxies, using the deepest IR data from Spitzer and Herschel in the GOODS-Hers…
The NuSTAR Extragalactic Surveys: The Number Counts of Active Galactic Nuclei and the Resolved Fraction of the Cosmic X-Ray Background
Harrison, F. A.; Hornstrup, A.; Stern, D. +41 more
We present the 3-8 keV and 8-24 keV number counts of active galactic nuclei (AGNs) identified in the Nuclear Spectroscopic Telescope Array (NuSTAR) extragalactic surveys. NuSTAR has now resolved 33%-39% of the X-ray background in the 8-24 keV band, directly identifying AGNs with obscuring columns up to ∼ {10}25 {{cm}}-2. In t…
Evidence for a Systematic Offset of -0.25 mas in the Gaia DR1 Parallaxes
Torres, Guillermo; Stassun, Keivan G.
We test the parallaxes reported in the Gaia first data release using the sample of eclipsing binaries with accurate, empirical distances from Stassun & Torres. We find an average offset of -0.25 ± 0.05 mas in the sense of the Gaia parallaxes being too small (I.e., the distances too long). The offset does not depend strongly on obvious paramete…
Lyman Continuum Escape Fraction of Star-forming Dwarf Galaxies at z ∼ 1
Teplitz, Harry I.; Rutkowski, Michael J.; Scarlata, Claudia +10 more
To date, no direct detection of Lyman continuum emission has been measured for intermediate-redshift (z∼ 1) star-forming galaxies. We combine Hubble Space Telescope grism spectroscopy with GALEX UV and ground-based optical imaging to extend the search for escaping Lyman continuum to a large (∼600) sample of z∼ 1 low-mass ({log}(\bar{M}) ≃ 9.3{M}
The Afterglow and Early-type Host Galaxy of the Short GRB 150101B at z = 0.1343
Berger, E.; Smith, N.; Zaritsky, D. +14 more
We present the discovery of the X-ray and optical afterglows of the short-duration GRB 150101B, pinpointing the event to an early-type host galaxy at z = 0.1343 ± 0.0030. This makes GRB 150101B the most nearby short gamma-ray burst (GRB) with an early-type host galaxy discovered to date. Fitting the spectral energy distribution of the host galaxy …
Stellar parametrization from Gaia RVS spectra
Allende Prieto, C.; Recio-Blanco, A.; de Laverny, P. +7 more
Context. Among the myriad of data collected by the ESA Gaia satellite, about 150 million spectra will be delivered by the Radial Velocity Spectrometer (RVS) for stars as faint as GRVS~ 16. A specific stellar parametrization will be performed on most of these RVS spectra, I.e. those with enough high signal-to-noise ratio (S/N), which sho…
Planck 2015 results. VI. LFI mapmaking
Bernard, J. -P.; Planck Collaboration; Ade, P. A. R. +198 more
This paper describes the mapmaking procedure applied to Planck Low Frequency Instrument (LFI) data. The mapmaking step takes as input the calibrated timelines and pointing information. The main products are sky maps of I, Q, and U Stokes components. For the first time, we present polarization maps at LFI frequencies. The mapmaking algorithm is bas…
An Ultraviolet Spectrum of the Tidal Disruption Flare ASASSN-14li
Fruchter, Andrew S.; Filippenko, Alexei V.; Ramirez-Ruiz, Enrico +18 more
We present a Hubble Space Telescope Space Telescope Imaging Spectrograph spectrum of ASASSN-14li, the first rest-frame ultraviolet (UV) spectrum of a tidal disruption flare (TDF). The underlying continuum is well fit by a blackbody with {T}{UV}=3.5× {10}4 K, an order of magnitude smaller than the temperature inferred from X-r…