Search Publications
The Inner Disk Structure, Disk-Planet Interactions, and Temporal Evolution in the β Pictoris System: A Two-epoch HST/STIS Coronagraphic Study
Schneider, Glenn; Apai, Dániel; Wyatt, Mark C. +5 more
We present deep Hubble Space Telescope/Space Telescope Imaging Spectrograph coronagraphic images of the β Pic debris disk obtained at two epochs separated by 15 yr. The new images and the re-reduction of the 1997 data provide the most sensitive and detailed views of the disk at optical wavelengths as well as the yet smallest inner working angle op…
A Luminous Red Nova in M31 and its Progenitor System
Steele, I. A.; Bode, M. F.; Darnley, M. J. +1 more
We present observations of M31LRN 2015 (MASTER OT J004207.99+405501.1), discovered in M31 in 2015 January, and identified as a rare and enigmatic luminous red nova (LRN). Spectroscopic and photometric observations obtained by the Liverpool Telescope showed the LRN becoming extremely red as it faded from its {{M}V}=-9.4+/- 0.2 peak. Earl…
The Formation of IRIS Diagnostics. VI. The Diagnostic Potential of the C II Lines at 133.5 nm in the Solar Atmosphere
De Pontieu, Bart; Carlsson, Mats; Leenaarts, Jorrit +1 more
We use 3D radiation magnetohydrodynamic models to investigate how the thermodynamic quantities in the simulation are encoded in observable quantities, thus exploring the diagnostic potential of the C ii 133.5 nm lines. We find that the line core intensity is correlated with the temperature at the formation height but the correlation is rather weak…
ALMA Observations of Warm Dense Gas in NGC 1614—Breaking of the Star Formation Law in the Central Kiloparsec
Sanders, D. B.; Inami, H.; Murphy, E. J. +20 more
We present ALMA Cycle-0 observations of the CO (6-5) line emission and of the 435 µm dust continuum emission in the central kiloparsec of NGC 1614, a local luminous infrared galaxy at a distance of 67.8 Mpc (1{\prime \prime }= 329 pc). The CO emission is well resolved by the ALMA beam (0.''26 × 0.''20) into a circumnuclear ring, w…
FUV Variability of HD 189733. Is the Star Accreting Material From Its Hot Jupiter?
Micela, G.; Sciortino, S.; Pillitteri, I. +3 more
Hot Jupiters are subject to strong irradiation from their host stars and, as a consequence, they do evaporate. They can also interact with the parent stars by means of tides and magnetic fields. Both phenomena have strong implications for the evolution of these systems. Here we present time-resolved spectroscopy of HD 189733 observed with the Cosm…
The NuSTAR Extragalactic Survey: First Direct Measurements of the ≳10 KeV X-Ray Luminosity Function for Active Galactic Nuclei at z>0.1
Harrison, F. A.; Wik, D. R.; Stern, D. +34 more
We present the first direct measurements of the rest-frame 10-40 keV X-ray luminosity function (XLF) of active galactic nuclei (AGNs) based on a sample of 94 sources at 0.1 < z < 3, selected at 8-24 keV energies from sources in the Nuclear Spectroscopic Telescope Array (NuSTAR) extragalactic survey program. Our results are consistent with th…
Circumstellar Dust around AGB Stars and Implications for Infrared Emission from Galaxies
Conroy, Charlie; Johnson, Benjamin D.; Villaume, Alexa
Stellar population synthesis (SPS) models are used to infer many galactic properties including star formation histories, metallicities, and stellar and dust masses. However, most SPS models neglect the effect of circumstellar dust shells around evolved stars and it is unclear to what extent they impact the analysis of spectral energy distributions…
Sixteen Years of Ulysses Interstellar Dust Measurements in the Solar System. I. Mass Distribution and Gas-to-dust Mass Ratio
Krüger, Harald; Grün, Eberhard; Sterken, Veerle J. +1 more
In the early 1990s, contemporary interstellar dust penetrating deep into the heliosphere was identified with the in situ dust detector on board the Ulysses spacecraft. Between 1992 and the end of 2007 Ulysses monitored the interstellar dust stream. The interstellar grains act as tracers of the physical conditions in the local interstellar medium (…
NuSTAR Hard X-Ray Survey of the Galactic Center Region I: Hard X-Ray Morphology and Spectroscopy of the Diffuse Emission
Hailey, Charles J.; Mori, Kaya; Giommi, Paolo +35 more
We present the first sub-arcminute images of the Galactic Center above 10 keV, obtained with NuSTAR. NuSTAR resolves the hard X-ray source IGR J17456-2901 into non-thermal X-ray filaments, molecular clouds, point sources, and a previously unknown central component of hard X-ray emission (CHXE). NuSTAR detects four non-thermal X-ray filaments, exte…
A Comprehensive Statistical Assessment of Star-Planet Interaction
Wright, Jason T.; Gallo, Elena; Miller, Brendan P. +1 more
We investigate whether magnetic interaction between close-in giant planets and their host stars produce observable statistical enhancements in stellar coronal or chromospheric activity. New Chandra observations of 12 nearby (d < 60 pc) planet-hosting solar analogs are combined with archival Chandra, XMM-Newton, and ROSAT coverage of 11 similar …