Search Publications
A Comparison of Rest-frame Ultraviolet and Optical Emission-line Diagnostics in the Lensed Galaxy SDSS J1723+3411 at Redshift z = 1.3293
Rigby, J. R.; Momcheva, Ivelina; Brammer, Gabriel +13 more
For the extremely bright lensed galaxy SDSS J1723+3411 at z = 1.3293, we analyze spatially integrated MMT, Keck, and Hubble Space Telescope spectra that fully cover the rest-frame wavelength range of 1400-7200 Å. We also analyze near-IR spectra from Gemini that cover Hα for a portion of the lensed arc. We report fluxes for 42 detected emission lin…
A Characterization of the Circumstellar Gas of WD 1124-293 Using Cloudy
Dufour, Patrick; Steele, Amy; Debes, John +2 more
Between 30% and 50% of white dwarfs (WDs) show heavy elements in their atmospheres. This pollution is thought to arise from the accretion of planetesimals perturbed by outer planet(s) to within the WD's tidal disruption radius. A small fraction of these WDs show either emission or absorption from circumstellar (C-S) gas. The abundances of metals i…
Measuring cosmic density of neutral hydrogen via stacking the DINGO-VLA data
Brough, S.; Staveley-Smith, Lister; Holwerda, B. W. +13 more
We use the 21-cm emission-line data from the Deep Investigation of Neutral Gas Origin-Very Large Array (DINGO-VLA) project to study the atomic hydrogen gas H I of the Universe at redshifts z < 0.1. Results are obtained using a stacking analysis, combining the H I signals from 3622 galaxies extracted from 267 VLA pointings in the G09 field of th…
The Carbon-to-H2, CO-to-H2 conversion factors, and carbon abundance on kiloparsec scales in nearby galaxies
Gao, Yu; Zhao, Yinghe; Jiao, Qian
Using the atomic carbon [C I] ($^{3} \rm P_{1} \rightarrow {\rm ^3 P}_{0}$) and [C I] ($^{3} \rm P_{2} \rightarrow {\rm ^3 P}_{1}$) emission {hereafter [C I] (1 - 0) and [C I] (2 - 1), respectively} maps observed with the Herschel Space Observatory, and CO (1 - 0), H I, infrared and submm maps from literatures, we estimate the [C I]-to-H2
Potential Black Hole Seeding of the Spiral Galaxy NGC 4424 via an Infalling Star Cluster
Soria, Roberto; Ciambur, Bogdan C.; Swartz, Douglas A. +2 more
Galaxies can grow through their mutual gravitational attraction and subsequent union. While orbiting a regular high-surface-brightness galaxy, the body of a low-mass galaxy can be stripped away. However, the stellar heart of the infalling galaxy, if represented by a tightly bound nuclear star cluster, is more resilient. From archival Hubble Space …
The BepiColombo Laser Altimeter
Lara, L. M.; Oberst, J.; Thomas, N. +48 more
The BepiColombo Laser Altimeter (BELA) is the first European laser altimeter constructed for interplanetary flight. BELA uses a 50 mJ pulsed Nd:YAG laser operating at 10 Hz with a 20 cm aperture receiver to perform the ranging. The instrument also uses a digital approach for range detection and pulse analysis. The ranging accuracy is expected to b…
The Core Mass Function in the Orion Nebula Cluster Region: What Determines the Final Stellar Masses?
Sanhueza, Patricio; Mairs, Steve; Nakamura, Fumitaka +29 more
Applying dendrogram analysis to the CARMA-NRO C18O (J = 1-0) data having an angular resolution of ∼8″, we identified 692 dense cores in the Orion Nebula Cluster region. Using this core sample, we compare the core and initial stellar mass functions in the same area to quantify the step from cores to stars. About 22% of the identified cor…
Precise Ages of Field Stars from White Dwarf Companions in Gaia DR2
Qiu, Dan; Tian, Hai-Jun; Liu, Gao-Chao +5 more
We analyze 4050 wide binary star systems involving a white dwarf (WD) and usually a main-sequence (MS) star, drawn from the large sample assembled by Tian et al. Using the modeling code BASE-9, we determine the system's ages, the WD progenitors' zero-age MS masses, the extinction values (AV), and the distance moduli. Discarding the case…
Idunn Mons: Evidence for Ongoing Volcano-tectonic Activity and Atmospheric Implications on Venus
D'Incecco, P.; Filiberto, J.; López, I. +2 more
In 2010 the ESA Venus Express Visible and Infrared Thermal Imaging Spectrometer (VIRTIS) instrument first observed 1 µm emissivity anomalies over the top and eastern flank of Idunn Mons (46° S; 146° W), a 200 km wide volcano located in Imdr Regio, a volcano-dominated large volcanic rise of Venus. The anomalies suggest the presence of chemica…
Spatially Resolved RGS Analysis of Kepler's Supernova Remnant
Katsuda, Satoru; Sato, Toshiki; Hughes, John P. +4 more
The distribution and kinematics of the circumstellar medium (CSM) around a supernova remnant (SNR) tell us useful information about the explosion of its natal supernova (SN). Kepler's SNR, the remnant of SN 1604, is widely regarded to be of Type Ia origin. Its shock is moving through a dense, asymmetric CSM. The presence of this dense gas suggests…