Search Publications
A Comparison of X-Ray and Optical Emission in Cassiopeia A
Fesen, Robert A.; Patnaude, Daniel J.
Broadband optical and narrowband Si XIII X-ray images of the young Galactic supernova remnant Cassiopeia A (Cas A) obtained over several decades are used to investigate spatial and temporal emission correlations on both large and small angular scales. The data examined consist of optical and near-infrared ground-based and Hubble Space Telescope im…
Determining Inclinations of Active Galactic Nuclei via Their Narrow-line Region Kinematics. II. Correlation with Observed Properties
Turner, T. J.; Kraemer, S. B.; Crenshaw, D. M. +2 more
Active galactic nuclei (AGNs) are axisymmetric systems to first order; their observed properties are likely strong functions of inclination with respect to our line of sight, yet the specific inclinations of all but a few AGNs are generally unknown. By determining the inclinations and geometries of nearby Seyfert galaxies using the kinematics of t…
Hubble Space Telescope Near-ultraviolet Spectroscopy of the Bright CEMP-no Star BD+44°493
Smith, Verne V.; Beers, Timothy C.; Placco, Vinicius M. +10 more
We present an elemental-abundance analysis, in the near-ultraviolet (NUV) spectral range, for the extremely metal-poor star BD+44°493 a ninth magnitude subgiant with [Fe/H] =-3.8 and enhanced carbon, based on data acquired with the Space Telescope Imaging Spectrograph on the Hubble Space Telescope. This star is the brightest example of a class of …
Star Formation Bimodality in Early-type Galaxies
Riguccini, L.; Amblard, A.; Temi, P. +3 more
We compute the properties of a sample of 221 local, early-type galaxies with a spectral energy distribution (SED) modeling software, CIGALEMC. Concentrating on the star-forming (SF) activity and dust contents, we derive parameters such as the specific star formation rate (sSFR), the dust luminosity, dust mass, and temperature. In our sample, 52% i…
NGC 1266 as a Local Candidate for Rapid Cessation of Star Formation
Krajnović, Davor; Emsellem, Eric; Sarzi, Marc +28 more
We present new Spectrographic Areal Unit for Research on Optical Nebulae (SAURON) integral-field spectroscopy and Swift Ultraviolet Optical Telescope (UVOT) observations of molecular outflow host galaxy NGC 1266 that indicate NGC 1266 has experienced a rapid cessation of star formation. Both the SAURON maps of stellar population age and the Swift …
The Gould's Belt Very Large Array Survey. III. The Orion Region
Kounkel, Marina; Rodríguez, Luis F.; Loinard, Laurent +11 more
We present results from a high-sensitivity (60 µJy), large-scale (2.26 deg2) survey obtained with the Karl G. Jansky Very Large Array as part of the Gould's Belt Survey program. We detected 374 and 354 sources at 4.5 and 7.5 GHz, respectively. Of these, 148 are associated with previously known young stellar objects (YSOs). Another…
Do Interacting Coronal Mass Ejections Play a Role in Solar Energetic Particle Events?
Vourlidas, A.; Kahler, S. W.
Gradual solar energetic (E > 10 MeV) particle (SEP) events are produced in shocks driven by fast and wide coronal mass ejections (CMEs). With a set of western hemisphere 20 MeV SEP events, we test the possibility that SEP peak intensities, Ip, are enhanced by interactions of their associated CMEs with preceding CMEs (preCMEs) launched during th…
Direct Evidence of an Eruptive, Filament-hosting Magnetic Flux Rope Leading to a Fast Solar Coronal Mass Ejection
Chen, Bin; Gary, D. E.; Bastian, T. S.
Magnetic flux ropes (MFRs) are believed to be at the heart of solar coronal mass ejections (CMEs). A well-known example is the prominence cavity in the low corona that sometimes makes up a three-part white-light (WL) CME upon its eruption. Such a system, which is usually observed in quiet-Sun regions, has long been suggested to be the manifestatio…
Very Late Photometry of SN 2011fe
Ruiter, A. J.; Seitenzahl, I. R.; Kerzendorf, W. E. +1 more
The Type Ia supernova SN 2011fe is one of the closest supernovae of the past decades. Due to its proximity and low dust extinction, this object provides a very rare opportunity to study the extremely late time evolution (>900 days) of thermonuclear supernovae. In this Letter, we present our photometric data of SN 2011fe taken at an unprecedente…
Variability of the High-velocity Outflow in the Quasar PDS 456
Behar, E.; Turner, T. J.; Reeves, J. N. +9 more
We present a comparison of two Suzaku X-ray observations of the nearby (z = 0.184), luminous (L bol ~ 1047 erg s-1) type I quasar, PDS 456. A new 125 ks Suzaku observation in 2011 caught the quasar during a period of low X-ray flux and with a hard X-ray spectrum, in contrast with a previous 190 ks Suzaku observatio…