Search Publications
The Sloan Digital Sky Survey Quasar Catalog: Fourteenth data release
Green, Paul J.; Pâris, Isabelle; Petitjean, Patrick +38 more
We present the data release 14 Quasar catalog (DR14Q) from the extended Baryon Oscillation Spectroscopic Survey (eBOSS) of the Sloan Digital Sky Survey IV (SDSS-IV). This catalog includes all SDSS-IV/eBOSS objects that were spectroscopically targeted as quasar candidates and that are confirmed as quasars via a new automated procedure combined with…
The 105-Month Swift-BAT All-sky Hard X-Ray Survey
Cenko, S. Bradley; Schawinski, Kevin; Koss, Michael +10 more
We present a catalog of hard X-ray sources detected in the first 105 months of observations with the Burst Alert Telescope (BAT) coded-mask imager on board the Swift observatory. The 105-month Swift-BAT survey is a uniform hard X-ray all-sky survey with a sensitivity of 8.40× {10}-12 {erg} {{{s}}}-1 {cm}}-2 over 90…
Discovery of pulsations from NGC 300 ULX1 and its fast period evolution
Haberl, F.; Vasilopoulos, G.; Maitra, C. +1 more
The supernova impostor SN 2010da located in the nearby galaxy NGC 300, later identified as a likely supergiant B[e] high-mass X-ray binary, was simultaneously observed by NuSTAR and XMM-Newton between 2016 December 16 and 20, over a total time span of ∼310 ks. We report the discovery of a strong periodic modulation in the X-ray flux with a pulse p…
Observations of the missing baryons in the warm-hot intergalactic medium
Piro, L.; Shull, J. M.; Fiore, F. +18 more
It has been known for decades that the observed number of baryons in the local Universe falls about 30-40 per cent short1,2 of the total number of baryons predicted3 by Big Bang nucleosynthesis, as inferred4,5 from density fluctuations of the cosmic microwave background and seen during the first 2-3 billion years o…
Ground-based detection of an extended helium atmosphere in the Saturn-mass exoplanet WASP-69b
Henning, Thomas; Dreizler, Stefan; Sánchez-López, Alejandro +25 more
Hot gas giant exoplanets can lose part of their atmosphere due to strong stellar irradiation, and these losses can affect their physical and chemical evolution. Studies of atmospheric escape from exoplanets have mostly relied on space-based observations of the hydrogen Lyman-α line in the far ultraviolet region, which is strongly affected by inter…
The evolution of the X-ray afterglow emission of GW 170817/ GRB 170817A in XMM-Newton observations
Covino, S.; D'Avanzo, P.; Campana, S. +12 more
We report our observation of the short gamma-ray burst (GRB) GRB 170817A, associated to the binary neutron star merger gravitational wave (GW) event GW 170817, performed in the X-ray band with XMM-Newton 135 d after the event (on 29 December, 2017). We find evidence for a flattening of the X-ray light curve with respect to the previously observed …
Explaining changing-look AGN with state transition triggered by rapid mass accretion rate drop
Done, Chris; Noda, Hirofumi
We model the broad-band (optical/UV and X-ray) continuum spectrum of the `changing-look' active galactic nucleus (AGN) Mrk 1018, as it fades from Seyfert 1 to 1.9 in ∼ 8 years. The brightest spectrum, with Eddington ratio L/LEdd ∼ 0.08 has a typical type 1 AGN continuum, with a strong `soft X-ray excess' spanning between the UV and soft…
A physical model of the broad-band continuum of AGN and its implications for the UV/X relation and optical variability
Done, Chris; Kubota, Aya
We develop a new spectral model for the broad-band spectral energy distribution (SED) of active galactic nuclei (AGN). This includes an outer standard disc, an inner warm Comptonizing region to produce the soft X-ray excess and a hot corona. We tie these together energetically by assuming Novikov-Thorne emissivity, and use this to define a size sc…
A Population of Bona Fide Intermediate-mass Black Holes Identified as Low-luminosity Active Galactic Nuclei
Boutsia, Konstantina; Chilingarian, Igor V.; Zolotukhin, Ivan Yu. +4 more
Nearly every massive galaxy harbors a supermassive black hole (SMBH) in its nucleus. SMBH masses are millions to billions of solar mass, and they correlate with properties of spheroids of their host galaxies. While the SMBH growth channels, mergers, and gas accretion are well established, their origin remains uncertain: they could have emerged eit…
Hubble PanCET: an extended upper atmosphere of neutral hydrogen around the warm Neptune GJ 3470b
Sanz-Forcada, J.; Ehrenreich, D.; Lecavelier des Etangs, A. +16 more
GJ 3470b is a warm Neptune transiting an M-dwarf star at the edge of the evaporation desert. It offers the possibility of investigating how low-mass, close-in exoplanets evolve under the irradiation from their host stars. We observed three transits of GJ 3470b in the Lyman-α line with the Hubble Space Telescope (HST) as part of the Panchromatic Co…