Search Publications
Confirming Herschel Candidate Protoclusters from ALMA/VLA CO Observations
Pérez-Fournon, I.; Valtchanov, I.; Clements, D. L. +11 more
ALMA 870 µm continuum imaging has uncovered a population of blends of multiple dusty star-forming galaxies (DSFGs) in sources originally detected with the Herschel Space Observatory. However, their pairwise separations are much smaller than what is found by ALMA follow-up of other single-dish surveys or expected from theoretical simulations.…
Weighing the Darkness: Astrometric Mass Measurement of Hidden Stellar Companions Using Gaia
Breivik, Katelyn; Andrews, Jeff J.; Chatterjee, Sourav
In astrometric binaries, the presence of a dark, unseen star can be inferred from the gravitational pull it induces on its luminous binary companion. While the orbit of such binaries can be characterized with precise astrometric measurements, constraints made from astrometry alone are not enough to measure the component masses. In this work, we de…
Discovery of Highly Blueshifted Broad Balmer and Metastable Helium Absorption Lines in a Tidal Disruption Event
Cenko, S. B.; Veilleux, S.; Foley, Ryan J. +25 more
We report the discovery of nonstellar hydrogen Balmer and metastable helium absorption lines accompanying a transient, high-velocity (0.05c) broad absorption line (BAL) system in the optical spectra of the tidal disruption event (TDE) AT2018zr (z = 0.071). In the Hubble Space Telescope UV spectra, absorption of high- and low-ionization lines is al…
Slowing of the Solar Wind in the Outer Heliosphere
Stern, S. Alan; Weaver, Harold A.; Young, Leslie A. +15 more
This study provides a deeper understanding of how the solar wind evolves with increasing distance from the Sun as it encounters an increasing amount of interstellar material. This work extends our prior work by (1) extending the solar wind proton data radial profiles for New Horizons (NH) out to nearly 43 au, (2) quantifying the observed amount of…
The Main Sequence at z ∼ 1.3 Contains a Sizable Fraction of Galaxies with Compact Star Formation Sizes: A New Population of Early Post-starbursts?
Daddi, E.; Elbaz, D.; Le Floc'h, E. +20 more
Atacama Large Millimeter/submillimeter Array (ALMA) measurements for 93 Herschel-selected galaxies at 1.1 ≤ z ≤ 1.7 in COSMOS reveal a sizable (>29%) population with compact star formation (SF) sizes, lying on average >×3.6 below the optical stellar mass (M ⋆)-size relation of disks. This sample widely spans the star-forming main …
Flaring Activity of Proxima Centauri from TESS Observations: Quasiperiodic Oscillations during Flare Decay and Inferences on the Habitability of Proxima b
Pál, András; Moór, Attila; Vida, Krisztián +3 more
We analyze the light curve of the M5.5 dwarf Proxima Centauri obtained by the Transiting Exoplanet Survey Satellite (TESS) in Sectors 11 and 12. In the ≈50 day long light curve we identified and analyzed 72 flare events. The flare rate was 1.49 events per day; in total, 7.2% of the observing time was classified as flaring. The estimated flare ener…
Back to the Lithium Plateau with the [Fe/H] < -6 Star J0023+0307
Aguado, David S.; Allende Prieto, Carlos; Rebolo, Rafael +1 more
We present an analysis of the Ultraviolet and Visual Echelle Spectrograph (UVES) high-resolution spectroscopic observations at the 8.2 m Very Large Telescope of J0023+0307, a main-sequence extremely iron-poor dwarf star. We are unable to detect iron lines in the spectrum but derive [Fe/H] < -6.1 from the Ca II resonance lines assuming [Ca/Fe] ≥…
The SPIRITS Sample of Luminous Infrared Transients: Uncovering Hidden Supernovae and Dusty Stellar Outbursts in Nearby Galaxies
Williams, Robert E.; Kilpatrick, Charles D.; Tinyanont, Samaporn +23 more
We present a systematic study of the most luminous (M IR [Vega magnitudes] brighter than -14) infrared (IR) transients discovered by the SPitzer InfraRed Intensive Transients Survey (SPIRITS) between 2014 and 2018 in nearby galaxies (D < 35 Mpc). The sample consists of nine events that span peak IR luminosities of M [4.5],peak
The COS CGM Compendium. II. Metallicities of the Partial and Lyman Limit Systems at z ≲ 1
Lehner, Nicolas; Howk, J. Christopher; O'Meara, John M. +3 more
We present the results from our COS circumgalactic medium (CGM) compendium (CCC), a survey of the CGM at z ≲ 1 using H I-selected absorbers with 15 < {log}{N}{{H}{{I}}} < 19. We focus here on 82 partial Lyman limit systems (pLLSs, 16.2 ≤ {log}{N}{{H}{{I}}} < 17.2) and 29 LLSs (17.2 ≤ {log}{N}{{H}{{I}}} <…
Evidence for Sub-Chandrasekhar Type Ia Supernovae from Stellar Abundances in Dwarf Galaxies
Kovalev, Mikhail; McWilliam, Andrew; Shen, Ken J. +6 more
There is no consensus on the progenitors of Type Ia supernovae (SNe Ia) despite their importance for cosmology and chemical evolution. We address this question using our previously published catalogs of Mg, Si, Ca, Cr, Fe, Co, and Ni abundances in dwarf galaxy satellites of the Milky Way (MW) to constrain the mass at which the white dwarf (WD) exp…