Search Publications
Spectroscopic Confirmation and Velocity Dispersions for 20 Planck Galaxy Clusters at 0.16 < z < 0.78
Chary, Ranga-Ram; Stern, Daniel; Shim, Hyunjin +8 more
We present Gemini and Keck spectroscopic redshifts and velocity dispersions for 20 clusters detected via the Sunyaev-Zel’dovich (SZ) effect by the Planck space mission, with estimated masses in the range 2.3× {10}14 {M}⊙ < {M}500{Pl}< 9.4× {10}14 {M}⊙ . Cluster members were se…
Resurrecting the Power-law, Intermediate, and Logamediate Inflations in the DBI Scenario with Constant Sound Speed
Karami, Kayoomars; Rezazadeh, Kazem; Amani, Roonak +1 more
We investigate the power-law, intermediate, and logamediate inflationary models in the framework of DBI non-canonical scalar field with constant sound speed. In the DBI setting, we first represent the power spectrum of both scalar density and tensor gravitational perturbations. Then, we derive different inflationary observables including the scala…
On the Transition of the Galaxy Quenching Mode at 0.5 < z < 1 in CANDELS
Barro, Guillermo; Pérez-González, Pablo G.; Bell, Eric F. +19 more
We investigate the galaxy quenching process at intermediate redshift using a sample of ∼4400 galaxies with M * > 109 M ⊙ between redshift 0.5 and 1.0 in all five CANDELS fields. We divide this sample, using the integrated specific star formation rate (sSFR), into four subgroups: star-forming galaxies (SFGs) abov…
Jet-related Excitation of the [C II] Emission in the Active Galaxy NGC 4258 with SOFIA
Appleton, P. N.; Guillard, P.; Togi, A. +7 more
We detect widespread [C II] 157.7 µm emission from the inner 5 kpc of the active galaxy NGC 4258 with the SOFIA integral field spectrometer FIFI-LS. The emission is found to be associated with warm H2, distributed along and beyond the end of the southern jet, in a zone known to contain shock-excited optical filaments. It is also a…
What We Learn from the X-Ray Grating Spectra of Nova SMC 2016
Rauch, T.; Della Valle, M.; Behar, E. +17 more
Nova SMC 2016 has been the most luminous nova known in the direction of the Magellanic Clouds. It turned into a very luminous supersoft X-ray source between days 16 and 28 after the optical maximum. We observed it with Chandra, the HRC-S camera, and the Low Energy Transmission Grating on 2016 November and 2017 January (days 39 and 88 after optical…
Kepler-503b: An Object at the Hydrogen Burning Mass Limit Orbiting a Subgiant Star
Schneider, Donald P.; Mahadevan, Suvrath; Majewski, Steven R. +10 more
Using spectroscopic radial velocities with the Apache Point Observatory Galaxy Evolution Experiment (APOGEE) instrument and Gaia distance estimates, we demonstrate that Kepler-503b, currently considered a validated Kepler planet, is in fact a brown-dwarf/low-mass star in a nearly circular 7.2-day orbit around a subgiant star. Using a mass estimate…
The GeMS/GSAOI Galactic Globular Cluster Survey (G4CS). I. A Pilot Study of the Stellar Populations in NGC 2298 and NGC 3201
Dotter, Aaron; Miller, Bryan W.; Monty, Stephanie +12 more
We present the first results from the GeMS/GSAOI Galactic Globular Cluster Survey (G4CS) of the Milky Way globular clusters NGC 3201 and NGC 2298. Using the Gemini South Adaptive Optics Imager (GSAOI), in tandem with the Gemini Multi-conjugate adaptive optics System (GeMS) on the 8.1 m Gemini-South telescope, we collected deep near-IR observations…
Near-infrared Stellar Populations in the Metal-poor, Dwarf Irregular Galaxies Sextans A and Leo A
Boyer, Martha L.; Meixner, Margaret; McDonald, Iain +3 more
We present JHK s observations of the metal-poor ([Fe/H] < -1.40) dwarf-irregular galaxies, Leo A and Sextans A, obtained with the WIYN High-resolution Infrared Camera at Kitt Peak. Their near-IR stellar populations are characterized by using a combination of color-magnitude diagrams and by identifying long-period variable stars. We…
Multi-spacecraft Observations of the Rotation and Nonradial Motion of a CME Flux Rope Causing an Intense Geomagnetic Storm
Wang, Rui; Liu, Ying D.; Hu, Huidong +2 more
We present an investigation of the rotation and nonradial motion of a coronal mass ejection (CME) from AR 12468 on 2015 December 16 using observations from SDO, SOHO, STEREO A, and Wind. The EUV and HMI observations of the source region show that the associated magnetic flux rope (MFR) axis pointed to the east before the eruption. We use a nonline…
Metal Deficiency in Two Massive Dead Galaxies at z ∼ 2
Vulcani, B.; Treu, T.; Jones, T. +8 more
Local massive early-type galaxies are believed to have completed most of their star formation ∼10 Gyr ago and evolved without having substantial star formation since that time. If so, their progenitors should have roughly solar stellar metallicities (Z *), comparable to their values today. We report the discovery of two lensed massive (…