Search Publications
Measuring Model-independent Masses and Radii of Single-lined Eclipsing Binaries: Analytic Precision Estimates
Stassun, Keivan G.; Stevens, Daniel J.; Gaudi, B. Scott
We derive analytic estimates for the ability with which one can obtain precise, empirical stellar masses and radii via single-lined eclipsing binaries (EBs) in the era of Gaia and TESS. Including stars that host transiting substellar companions, such single-lined EBs already number in the hundreds from ground-based transit surveys and will compris…
X-Ray Variability from the Ultraluminous Black Hole Candidate X-Ray Binary in the Globular Cluster RZ 2109
Kundu, Arunav; Dage, Kristen C.; Zepf, Stephen E. +3 more
We present the results of long-term monitoring of the X-ray emission from the ultraluminous X-ray source XMMU J122939.9+075333 in the extragalactic globular cluster RZ2109. The combination of the high X-ray luminosity, short-term X-ray variability, X-ray spectrum, and optical emission suggests that this system is likely an accreting black hole in …
The Cosmic Web around the Brightest Galaxies during the Epoch of Reionization
Trenti, Michele; Mutch, Simon J.; Ren, Keven
The most luminous galaxies at high redshift are generally considered to be hosted in massive dark-matter halos of comparable number density, hence residing at the center of over-densities/protoclusters. We assess the validity of this assumption by investigating the clustering around the brightest galaxies populating the cosmic web at redshift z ∼ …
Noble Gas Abundance Ratios Indicate the Agglomeration of 67P/Churyumov-Gerasimenko from Warmed-up Ice
Wurz, P.; Lunine, J. I.; Danger, G. +8 more
The origin of cometary volatiles remains a major open question in planetary science. Comets may have either agglomerated from crystalline ices condensed in the protosolar nebula (PSN) or from amorphous ice originating from the molecular cloud and interstellar medium. Here, based on the recent argon, krypton, and xenon measurements performed by the…
The Spectral Energy Distribution of the Hyperluminous, Hot Dust-obscured Galaxy W2246-0526
Shu, Xinwen; Knudsen, Kirsten K.; Fan, Lulu +1 more
Hot dust-obscured galaxies (Hot DOGs) are a luminous, dust-obscured population recently discovered in the WISE All-Sky survey. Multiwavelength follow-up observations suggest that they are mainly powered by accreting supermassive black holes (SMBHs), lying in dense environments, and being in the transition phase between extreme starburst and UV-bri…
Fermi Transient J1544-0649: A Flaring Radio-weak BL Lac
Ubertini, Pietro; Bazzano, Angela; Panessa, Francesca +6 more
On 2017 May 15, the FERMI/LAT gamma-ray telescope observed a transient source not present in any previous high-energy catalog: J1544-0649. It was visible for two consecutive weeks, with a flux peak on May 21. Subsequently observed by a Swift/XRT follow-up starting on May 26, the X-ray counterpart position was coincident with the optical transient …
The Second Nucleus of NGC 7727: Direct Evidence for the Formation and Evolution of an Ultracompact Dwarf Galaxy
Kelson, Daniel D.; Seitzer, Patrick; Whitmore, Bradley C. +2 more
We present new observations of the late-stage merger galaxy NGC 7727, including Hubble Space Telescope/WFPC2 images and long-slit spectra obtained with the Clay telescope. NGC 7727 is relatively luminous ({M}V = -21.7) and features two unequal tidal tails, various bluish arcs and star clusters, and two bright nuclei 480 pc apart in proj…
The Mass of the Cepheid V350 Sgr
Evans, Nancy Remage; Carpenter, Kenneth G.; Kober, Gladys V. +6 more
V350 Sgr is a classical Cepheid suitable for mass determination. It has a hot companion which is prominent in the ultraviolet (UV) and which is not itself a binary. We have obtained two high-resolution echelle spectra of the companion at orbital velocity maximum and minimum with the Space Telescope Imaging Spectrograph on the Hubble Space Telescop…
Statistical Investigation of Supersonic Downflows in the Transition Region above Sunspots
Tian, Hui; Prasad Choudhary, Debi; Samanta, Tanmoy
Downflows at supersonic speeds have been observed in the transition region (TR) above sunspots for more than three decades. These downflows are often seen in different TR spectral lines above sunspots. We have performed a statistical investigation of these downflows using a large sample that was missing previously. The Interface Region Imaging Spe…
A Globular Cluster Luminosity Function Distance to NGC 4993 Hosting a Binary Neutron Star Merger GW170817/GRB 170817A
Im, Myungshin; Lee, Myung Gyoon; Kang, Jisu
NGC 4993 hosts a binary neutron star merger, GW170817/GRB 170817A, emitting gravitational waves and electromagnetic waves. The distance to this galaxy is not well established. We select the globular cluster candidates from the Hubble Space Telescope (HST)/ACS F606W images of NGC 4993 in the archive, using the structural parameters of the detected …