Search Publications
Creation/destruction of ultra-wide binaries in tidal streams
Peñarrubia, Jorge
This paper uses statistical and N-body methods to explore a new mechanism to form binary stars with extremely large separations ( ${\gtrsim}0.1\, {\rm pc}$ ), whose origin is poorly understood. Here, ultra-wide binaries arise via chance entrapment of unrelated stars in tidal streams of disrupting clusters. It is shown that (i) the formation of ult…
Detection of Aerosols at Microbar Pressures in an Exoplanet Atmosphere
West, Robert; Swain, Mark R.; Estrela, Raissa +3 more
The formation of hazes at microbar pressures has been explored by theoretical models of exoplanet atmospheres to explain Rayleigh scattering and/or featureless transmission spectra; however observational evidence of aerosols in the low-pressure formation environments has proved elusive. Here, we show direct evidence of aerosols existing at ~1 micr…
First Cospatial Comparison of Stellar, Neutral-gas, and Ionized-gas Metallicities in a Metal-rich Galaxy: M83
Faucher-Giguère, Claude-André; Hafen, Zachary; Kumari, Nimisha +14 more
We carry out a comparative analysis of the metallicities from the stellar, neutral-gas, and ionized-gas components in the metal-rich spiral galaxy M83. We analyze spectroscopic observations taken with the Hubble Space Telescope, the Large Binocular Telescope, and the Very Large Telescope. We detect a clear depletion of the H I gas, as observed fro…
High-resolution Extinction Map in the Direction of the Strongly Obscured Bulge Fossil Fragment Liller 1
Pallanca, Cristina; Dalessandro, Emanuele; Ferraro, Francesco R. +11 more
We used optical images acquired with the Wide Field Camera of the Advanced Camera for Surveys on board the Hubble Space Telescope and near-infrared data from Gemini Multi-conjugate Adaptive Optics System (GeMS)/Gemini South Adaptive Optics Imager (GSAOI) to construct a high-resolution extinction map in the direction of the bulge stellar system Lil…
Solar Energetic Electron Events Associated with Hard X-Ray Flares
Krucker, Säm; Su, Yang; Mason, Glenn M. +3 more
We investigate 16 solar energetic electron (SEE) events measured by WIND/3DP with a double-power-law spectrum and the associated western hard X-ray (HXR) flares measured by RHESSI with good count statistics, from 2002 February to 2016 December. In all the 16 cases, the presence of an SEE power-law spectrum extending down to ≤5 keV at 1 au implies …
Discovery of new globular clusters in the Sagittarius dwarf galaxy
Minniti, D.; Rejkuba, M.; Ripepi, V. +14 more
Context. Globular clusters (GCs) are witnesses of the past accretion events onto the Milky Way. In particular, the GCs of the Sagittarius (Sgr) dwarf galaxy are important probes of an on-going merger.
Aims: Our main goal is to search for new GC members of this dwarf galaxy using the VISTA Variables in the Via Lactea Extended Survey (VVVX) nea…
The HETDEX Survey: The Lyα Escape Fraction from 3D-HST Emission-Line Galaxies at z ∼ 2
Finkelstein, Steven L.; Schneider, Donald P.; Janowiecki, Steven +13 more
In this work, we measure the Lyα escape fraction of 935 [O III]-emitting galaxies between 1.9 < z < 2.35 by comparing stacked spectra from the Hubble Space Telescope/WFC3's near-IR grism to corresponding stacks from the Hobby-Eberly Telescope Dark Energy Experiment's Internal Data Release 2. By measuring the stacks' Hβ to Lyα ratios, we dete…
The complex multi-component outflow of the Seyfert galaxy NGC 7130
Knapen, J. H.; Comerón, S.; Ramos Almeida, C. +1 more
Active galactic nuclei (AGN) are a key ingredient for understanding galactic evolution, as their activity is coupled to the host galaxy properties through feedback processes. AGN-driven outflows are one of the manifestations of this feedback. The laser guide star adaptive optics mode for MUSE at the VLT now permits us to study the innermost tens o…
Multiband variability of the TeV blazar PG 1553+113 with XMM-Newton
Gupta, Alok C.; Wiita, Paul J.; Gaur, Haritma +1 more
We present variability analyses of twenty pointed XMM-Newton observations of the high energy peaked TeV blazar PG 1553+113 taken during 2010-2018. We found intraday variability in the total X-ray energy range (0.3-10 keV) in 16 out of 19 light curves or a duty cycle of ~84 per cent. A discrete correlation function analysis of the intraday light cu…
SOFIA Observations of 30 Doradus. I. Far-infrared Dust Polarization and Implications for Grain Alignment and Disruption by Radiative Torques
Lee, Min-Young; Coudé, Simon; Soam, Archana +7 more
Located in the Large Magellanic Cloud and mostly irradiated by the massive star cluster R136, 30 Doradus is an ideal target to test the leading theory of grain alignment and rotational disruption by RAdiative Torques (RATs). Here, we use publicly available polarized thermal dust emission observations of 30 Doradus at 89, 154, and 214 µm usin…