Search Publications
z ~ 1 Lyα Emitters. I. The Luminosity Function
Cowie, Lennox L.; Barger, Amy J.; Wold, Isak G. B.
We construct a flux-limited sample of 135 candidate z ~ 1 Lyα emitters (LAEs) from Galaxy Evolution Explorer (GALEX) grism data using a new data cube search method. These LAEs have luminosities comparable to those at high redshifts and lie within a 7 Gyr gap present in existing LAE samples. We use archival and newly obtained optical spectra to ver…
Outflow Structure of the Quiet Sun Corona Probed by Spacecraft Radio Scintillations in Strong Scattering
Pätzold, Martin; Imamura, Takeshi; Ando, Hiroki +11 more
Radio scintillation observations have been unable to probe flow speeds in the low corona where the scattering of radio waves is exceedingly strong. Here we estimate outflow speeds continuously from the vicinity of the Sun to the outer corona (heliocentric distances of 1.5-20.5 solar radii) by applying the strong scattering theory to radio scintill…
Modeling the X-Rays from the Central Compact Object PSR J1852+0040 in Kesteven 79: Evidence for a Strongly Magnetized Neutron Star
Bogdanov, Slavko
I present modeling of the X-ray pulsations from the central compact object (CCO) PSR J1852+0040 in the Galactic supernova remnant Kesteven 79. In the context of thermal surface radiation from a rotating neutron star (NS), a conventional polar cap model can reproduce the broad, large-amplitude X-ray pulse only with a "pencil plus fan" beam emission…
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…