Search Publications
Old but Still Warm: Far-UV Detection of PSR B0950+08
Pavlov, G. G.; Guillot, S.; Kargaltsev, O. +3 more
We report on a Hubble Space Telescope detection of the nearby, old pulsar B0950+08 (d≃ 262 pc, spin-down age 17.5 Myr) in two far-ultraviolet (FUV) bands. We measured the mean flux densities {\bar{f}}ν =109+/- 6 nJy and 83 ± 14 nJy in the F125LP and F140LP filters (pivot wavelengths 1438 and 1528 Å). Using the FUV data together with pre…
The nearby Type Ibn supernova 2015G: signatures of asymmetry and progenitor constraints
Van Dyk, Schuyler D.; Filippenko, Alexei V.; Wood-Vasey, W. Michael +24 more
We present the results of an extensive observational campaign on the nearby Type Ibn SN 2015G, including data from radio through ultraviolet wavelengths. SN 2015G was asymmetric, showing late-time nebular lines redshifted by ∼1000 km s-1. It shared many features with the prototypical SN Ibn 2006jc, including extremely strong He I emissi…
A Catalog of Stellar Unified Properties (CATSUP) for 951 FGK-Stars within 30 pc
Smith, Graeme H.; Shkolnik, Evgenya L.; Somers, Garrett +6 more
Almost every star in our Galaxy is likely to harbor a terrestrial planet, but accurate measurements of an exoplanet’s mass and radius demand accurate knowledge of the properties of its host star. The imminent TESS and CHEOPS missions are slated to discover thousands of new exoplanets. Along with WFIRST, which will directly image nearby planets, th…
Peculiar architectures for the WASP-53 and WASP-81 planet-hosting systems★
Smalley, Barry; Hellier, Coel; Triaud, Amaury H. M. J. +16 more
We report the detection of two new systems containing transiting planets. Both were identified by WASP as worthy transiting planet candidates. Radial velocity observations quickly verified that the photometric signals were indeed produced by two transiting hot Jupiters. Our observations also show the presence of additional Doppler signals. In addi…
MC2: Subaru and Hubble Space Telescope Weak-lensing Analysis of the Double Radio Relic Galaxy Cluster PLCK G287.0+32.9
Koekemoer, Anton M.; Seitz, Stella; Gruen, Daniel +6 more
The second most significant detection of the Planck Sunyaev-Zel’dovich survey, PLCK G287.0+32.9 (z = 0.385), boasts two similarly bright radio relics and a radio halo. One radio relic is located ∼ 400 {kpc} NW of the X-ray peak and the other ∼ 2.8 Mpc to the SE. This large difference suggests that a complex merging scenario is required. A key miss…
Detection of a Hydrogen Corona in HST Lyα Images of Europa in Transit of Jupiter
Roth, Lorenz; Strobel, Darrell F.; Becker, Tracy M. +4 more
We report far-ultraviolet observations of Europa in transit of Jupiter obtained with the Space Telescope Imaging Spectrograph of the Hubble Space Telescope on six occasions between 2014 December and 2015 March. Absorption of Jupiter’s bright hydrogen Lyα dayglow is detected in a region several moon radii above the limb in all observations. The obs…
Thermally anomalous features in the subsurface of Enceladus's south polar terrain
Sotin, C.; Lorenz, R. D.; West, R. D. +15 more
Saturn's moon Enceladus is an active world. In 2005, the Cassini spacecraft witnessed for the first time water-rich jets venting from four anomalously warm fractures (called sulci) near its south pole1,2. Since then, several observations have provided evidence that the source of the material ejected from Enceladus is a large underground…
Star Formation at z = 2.481 in the Lensed Galaxy SDSS J1110+6459. II. What is Missed at the Normal Resolution of the Hubble Space Telescope?
Rigby, J. R.; Sharon, K.; Gladders, M. D. +6 more
For lensed galaxy SGAS J111020.0+645950.8 at redshift z = 2.481, which is magnified by a factor of 28 ± 8, we analyze the morphology of star formation, as traced by rest-frame ultraviolet emission, in both the highly magnified source plane and simulations of how this galaxy would appear without lensing magnification. Were this galaxy not lensed, b…
Milky Way Tomography with K and M Dwarf Stars: The Vertical Structure of the Galactic Disk
Yanny, Brian; Ferguson, Deborah; Gardner, Susan
We use the number density distributions of K and M dwarf stars with vertical height from the Galactic disk, determined using observations from the Sloan Digital Sky Survey, to probe the structure of the Milky Way disk across the survey’s footprint. Using photometric parallax as a distance estimator we analyze a sample of several million disk stars…
A dichotomy between the hard state spectral properties of black hole and neutron star X-ray binaries
Sunyaev, R.; Gilfanov, M.; Burke, M. J.
We analyse the spectra of black hole (BH) and neutron star (NS) X-ray binaries (XBs) in the hard state using archival RXTE observations. We find that there is a clear dichotomy in the strength of Comptonization between NS and BH sources, as measured by both the Compton y-parameter and the amplification factor A, with distinct groups of BH and NS X…