Search Publications
Discovery of a radio relic in the low mass, merging galaxy cluster PLCK G200.9-28.2
Wik, Daniel R.; Giacintucci, Simona; Venturi, Tiziana +5 more
Radio relics at the peripheries of galaxy clusters are tracers of the elusive cluster merger shocks. We report the discovery of a single radio relic in the galaxy cluster PLCK G200.9-28.2 (z = 0.22, M500 = 2.7 ± 0.2 × 1014 M⊙) using the Giant Metrewave Radio Telescope at 235 and 610 MHz and the Karl G. Jansky Very …
The Molecular Cloud S242: Physical Environment and Star-formation Activities
Dewangan, L. K.; Ojha, D. K.; Janardhan, P. +3 more
We present a multi-wavelength study to probe the star-formation (SF) processes on a larger scale (∼ 1\buildrel{\circ}\over{.} 05× 0\buildrel{\circ}\over{.} 56) around the S242 site. The S242 molecular cloud is depicted in a velocity range from -3.25 to 4.55 km s-1 and has a spatially elongated appearance. Based on the virial analysis, t…
Determining Empirical Stellar Masses and Radii from Transits and Gaia Parallaxes as Illustrated by Spitzer Observations of KELT-11b
Pepper, Joshua; Stassun, Keivan G.; Siverd, Robert J. +8 more
Using the Spitzer Space Telescope, we observed a transit at 3.6 µm of KELT-11b. We also observed three partial planetary transits from the ground. We simultaneously fit these observations, ground-based photometry from Pepper et al., radial velocity data from Pepper et al., and a spectral energy distribution (SED) model using catalog magnitud…
Electron temperature anisotropy regulation by whistler instability
Yoon, P. H.; Hwang, J.; Kim, H. P. +1 more
The solar wind electron temperature anisotropy is regulated by a number of physical processes, which include adiabatic expansion, electron Coulomb collisions, and microinstabilities. In the collisionless limit, the measured electron temperature anisotropy is constrained by the marginal threshold conditions for whistler (electromagnetic electron cy…
New ALMA constraints on the star-forming interstellar medium at low metallicity: a 50 pc view of the blue compact dwarf galaxy SBS 0335-052
Lebouteiller, V.; Madden, S. C.; Galliano, F. +8 more
Properties of the cold interstellar medium of low-metallicity galaxies are not well known due to the faintness and extremely small scale on which emission is expected. We present deep ALMA band 6 (230 GHz) observations of the nearby, low-metallicity (12 + log (O/H) = 7.25) blue compact dwarf galaxy SBS 0335-052 at an unprecedented resolution of 0.…
Robust predictions for an oscillatory bispectrum in Planck 2015 data from transient reductions in the speed of sound of the inflaton
Hu, Bin; Torrado, Jesús; Achúcarro, Ana
We update the search for features in the cosmic microwave background (CMB) power spectrum due to transient reductions in the speed of sound, using Planck 2015 CMB temperature and polarization data. We enlarge the parameter space to much higher oscillatory frequencies of the feature, and define a robust prior independent of the ansatz for the reduc…
The Kinematics of the Permitted C II λ6578 Line in a Large Sample of Planetary Nebulae
Suárez, Genaro; Richer, Michael G.; López, José Alberto +1 more
We present spectroscopic observations of the C II λ6578 permitted line for 83 lines of sight in 76 planetary nebulae at high spectral resolution, most of them obtained with the Manchester Echelle Spectrograph on the 2.1 m telescope at the Observatorio Astronómico Nacional on the Sierra San Pedro Mártir. We study the kinematics of the C II λ6578 pe…
New Fe I Level Energies and Line Identifications from Stellar Spectra. II. Initial Results from New Ultraviolet Spectra of Metal-poor Stars
Ayres, Thomas R.; Peterson, Ruth C.; Kurucz, Robert L.
The Fe I spectrum is critical to many areas of astrophysics, yet many of the high-lying levels remain uncharacterized. To remedy this deficiency, Peterson & Kurucz identified Fe I lines in archival ultraviolet and optical spectra of metal-poor stars, whose warm temperatures favor moderate Fe I excitation. Sixty-five new levels were recovered, …
Hale cycle and long-term trend in variation of galactic cosmic rays related to solar rotation
Mursula, K.; Gil, A.
Context. Galactic cosmic ray (GCR) intensities around solar minimum times are modulated by magnetic drifts that depend on the overall solar polarity. GCR intensities reach a higher but more narrow peak during negative minima than during positive minima. However, despite these higher intensities, the variation of GCRs over timescales of solar rotat…
ZFIRE: Similar Stellar Growth in Hα-emitting Cluster and Field Galaxies at z ~ 2
Papovich, Casey; Kewley, Lisa J.; Kacprzak, Glenn G. +13 more
We compare galaxy scaling relations as a function of environment at z∼ 2 with our ZFIRE survey12 where we have measured Hα fluxes for 90 star-forming galaxies selected from a mass-limited ({log}({M}\star /{M}⊙ )> 9) sample based on ZFOURGE.13 The cluster galaxies (37) are part of a confirmed system at…