Search Publications
An 600 pc View of the Strongly Lensed, Massive Main-sequence Galaxy J0901: A Baryon-dominated, Thick Turbulent Rotating Disk with a Clumpy Cold Gas Ring at z = 2.259
Lutz, D.; Förster Schreiber, N. M.; Genzel, R. +19 more
We present a high-resolution kinematic study of the massive main-sequence star-forming galaxy (SFG) SDSS J090122.37+181432.3 (J0901) at z = 2.259, using ~0.″36 Atacama Large Millimeter/submillimeter Array CO(3-2) and ~0.″1-0.″5 SINFONI/VLT Hα observations. J0901 is a rare, strongly lensed but otherwise normal massive ( $\mathrm{log}({M}_{\star }/{…
Elemental Abundances of the Super-Neptune WASP-107b's Host Star Using High-resolution, Near-infrared Spectroscopy
Souto, Diogo; Crossfield, Ian J. M.; Nordlander, Thomas +8 more
We present the first elemental abundance measurements of the K dwarf (K7V) exoplanet-host star WASP-107 using high-resolution (R ≃45,000), near-infrared (H- and K-band) spectra taken from Gemini-S/IGRINS. We use the previously determined physical parameters of the star from the literature and infer the abundances of 15 elements—C, N, O, Na, Mg, Al…
An X-Ray-dim "Isolated" Neutron Star in a Binary?
Shi, Jianrong; Ramsay, Gavin; Esamdin, Ali +13 more
We report the discovery of a dark companion to 2MASS J15274848+3536572 with an orbital period of 6.14 hr. Combining the radial velocity from LAMOST observations and modeling of the multiband light curve, one obtains a mass function of ≃0.131 M ⊙, an inclination of $45\buildrel{\circ}\over{.} {20}_{-0\buildrel{\circ}\over{.} \,20}^{+0\bu…
No Small-scale Radio Jets Here: Multiepoch Observations of Radio Continuum Structures in NGC 1068 with the VLBA
Fischer, Travis C.; Secrest, Nathan J.; Crenshaw, D. Michael +2 more
We present recent Very Long Baseline Array (VLBA) 5 GHz radio observations of the nearby, luminous Seyfert 2 galaxy NGC 1068 for comparison to similar VLBA observations made on 1997 April 26. By cross-correlating the positions of emitting regions across both epochs, we find that spatially resolved extranuclear radio knots in this system have subre…
Detection of Carbon Monoxide's 4.6 Micron Fundamental Band Structure in WASP-39b's Atmosphere with JWST NIRSpec G395H
Mikal-Evans, Thomas; Stevenson, Kevin B.; Kirk, James +29 more
Carbon monoxide (CO) is predicted to be the dominant carbon-bearing molecule in giant planet atmospheres and, along with water, is important for discerning the oxygen and therefore carbon-to-oxygen ratio of these planets. The fundamental absorption mode of CO has a broad, double-branched structure composed of many individual absorption lines from …
The Imprint of Clump Formation at High Redshift. II. The Chemistry of the Bulge
Fisher, Deanne B.; Nidever, David L.; Valenti, Elena +11 more
In Paper I, we showed that clumps in high-redshift galaxies, having a high star formation rate density (ΣSFR), produce disks with two tracks in the [Fe/H]-[α/Fe] chemical space, similar to that of the Milky Way's (MW's) thin+thick disks. Here we investigate the effect of clumps on the bulge's chemistry. The chemistry of the MW's bulge i…
The Stellar Mass-Black Hole Mass Relation at z 2 down to {{M }}_{\mathrm{BH}}∼ {10}(7} {M) _{⊙ } Determined by HETDEX
Ono, Yoshiaki; Ouchi, Masami; Finkelstein, Steven L. +14 more
We investigate the stellar mass-black hole mass ( ${{ \mathcal M }}_{* }\mbox{--}{{ \mathcal M }}_{\mathrm{BH}}$ ) relation with type 1 active galactic nuclei (AGNs) down to ${{ \mathcal M }}_{\mathrm{BH}}={10}^{7\,}{M}_{\odot }$ , corresponding to a ≃ -21 absolute magnitude in rest-frame ultraviolet, at z = 2-2.5. Exploiting the deep and large-ar…
SN 2022acko: The First Early Far-ultraviolet Spectra of a Type IIP Supernova
Van Dyk, Schuyler D.; Smith, Nathan; Hillier, D. John +41 more
We present five far- and near-ultraviolet spectra of the Type II plateau supernova, SN 2022acko, obtained 5, 6, 7, 19, and 21 days after explosion, all observed with the Hubble Space Telescope/Space Telescope Imaging Spectrograph. The first three epochs are earlier than any Type II plateau supernova has been observed in the far-ultraviolet reveali…
Near-IR Weak-lensing (NIRWL) Measurements in the CANDELS Fields. I. Point-spread Function Modeling and Systematics
Chary, Ranga-Ram; Taylor, Peter; Jee, M. James +5 more
We have undertaken a near-IR weak-lensing (NIRWL) analysis of the CANDELS HST/WFC3-IR F160W observations. With the Gaia proper motion–corrected catalog as an astrometric reference, we updated the astrometry of the five CANDELS mosaics and achieved an absolute alignment within 0.″02 ± 0.″02, on average, which is a factor of several superior to exis…
The Physical Thickness of Stellar Disks to z ∼ 2
Heckman, Timothy M.; Snyder, Gregory F.; Simons, Raymond C. +2 more
In local disk galaxies such as our Milky Way, older stars generally inhabit a thicker disk than their younger counterparts. Two competing models have attempted to explain this result: one in which stars first form in thin disks that gradually thicken with time through dynamical heating, and one in which stars form in thick disks at early times and…