Search Publications
Herschel Observations of Gas and Dust in the Unusual 49 Ceti Debris Disk
Dent, W. R. F.; Woitke, P.; Kamp, I. +12 more
We present far-IR/sub-mm imaging and spectroscopy of 49 Ceti, an unusual circumstellar disk around a nearby young A1V star. The system is famous for showing the dust properties of a debris disk, but the gas properties of a low-mass protoplanetary disk. The data were acquired with the Herschel Space Observatory PACS and SPIRE instruments, largely a…
Water Vapor in the Protoplanetary Disk of DG Tau
Pinte, C.; Ménard, F.; Woitke, P. +13 more
Water is key in the evolution of protoplanetary disks and the formation of comets and icy/water planets. While high-excitation water lines originating in the hot inner disk have been detected in several T Tauri stars (TTSs), water vapor from the outer disk, where most water ice reservoirs are stored, was only reported in the nearby TTS TW Hya. We …
Superluminous X-Rays from a Superluminous Supernova
Read, A. M.; Wheatley, P. J.; Levan, A. J. +2 more
The discovery of a population of superluminous supernovae (SLSNe), with peak luminosities a factor of ~100 brighter than normal supernovae (SNe; typically SLSNe have MV < -21), has shown an unexpected diversity in core-collapse SN properties. Numerous models have been postulated for the nature of these events, including a strong inte…
Plasma Composition in a Sigmoidal Anemone Active Region
van Driel-Gesztelyi, L.; Démoulin, P.; Baker, D. +4 more
Using spectra obtained by the EUV Imaging Spectrometer (EIS) instrument onboard Hinode, we present a detailed spatially resolved abundance map of an active region (AR)-coronal hole (CH) complex that covers an area of 359'' × 485''. The abundance map provides first ionization potential (FIP) bias levels in various coronal structures within the larg…
Herschel's "Cold Debris Disks": Background Galaxies or Quiescent Rims of Planetary Systems?
Krivov, A. V.; Eiroa, C.; Löhne, T. +24 more
Infrared excesses associated with debris disk host stars detected so far peak at wavelengths around ~100 µm or shorter. However, 6 out of 31 excess sources studied in the Herschel Open Time Key Programme, DUNES, have been seen to show significant—and in some cases extended—excess emission at 160 µm, which is larger than the 100 µ…
Sensitive Search for Radio Variables and Transients in the Extended Chandra Deep Field South
Frail, D. A.; Kulkarni, S. R.; Horesh, A. +3 more
We report on an analysis of the Extended Chandra Deep Field South (E-CDFS) region using archival data from the Very Large Array, with the goal of studying radio variability and transients at the sub-milliJansky level. The 49 epochs of E-CDFS observations at 1.4 GHz sample timescales from 1 day to 3 months. We find that only a fraction (1%) of unre…
Probing the Extreme Realm of Active Galactic Nucleus Feedback in the Massive Galaxy Cluster, RX J1532.9+3021
von der Linden, A.; Fabian, A. C.; Hlavacek-Larrondo, J. +7 more
We present a detailed Chandra, XMM-Newton, Very Large Array (VLA) and Hubble Space Telescope analysis of one of the strongest cool core clusters known, RX J1532.9+3021 (z = 0.3613). Using new, deep 90 ks Chandra observations, we confirm the presence of a western X-ray cavity or bubble, and report on a newly discovered eastern X-ray cavity. The tot…
Phobos as a D-type Captured Asteroid, Spectral Modeling from 0.25 to 4.0 µm
Pajola, M.; Barbieri, C.; Bertini, I. +6 more
This paper describes the spectral modeling of the surface of Phobos in the wavelength range between 0.25 and 4.0 µm. We use complementary data to cover this spectral range: the OSIRIS (Optical, Spectroscopic, and Infrared Remote Imaging System on board the ESA Rosetta spacecraft) reflectance spectrum that Pajola et al. merged with the VSK-KR…
Active Galactic Nucleus Black Hole Mass Estimates in the Era of Time Domain Astronomy
Treu, Tommaso; Malkan, Matthew; Kelly, Brandon C. +2 more
We investigate the dependence of the normalization of the high-frequency part of the X-ray and optical power spectral densities (PSDs) on black hole mass for a sample of 39 active galactic nuclei (AGNs) with black hole masses estimated from reverberation mapping or dynamical modeling. We obtained new Swift observations of PG 1426+015, which has th…
Outflows from Evolved Stars: The Rapidly Changing Fingers of CRL 618
Frank, Adam; Corradi, Romano L. M.; Balick, Bruce +4 more
Our ultimate goal is to probe the nature of the collimator of the outflows in the pre-planetary nebula CRL 618. CRL 618 is uniquely suited for this purpose owing to its multiple, bright, and carefully studied finger-shaped outflows east and west of its nucleus. We compare new Hubble Space Telescope images to images in the same filters observed as …