Search Publications
Coronal Heating Rate in the Slow Solar Wind
Telloni, Daniele; Zank, Gary P.; Adhikari, Laxman +59 more
This Letter reports the first observational estimate of the heating rate in the slowly expanding solar corona. The analysis exploits the simultaneous remote and local observations of the same coronal plasma volume, with the Solar Orbiter/Metis and the Parker Solar Probe instruments, respectively, and relies on the basic solar wind magnetohydrodyna…
The Fast X-Ray Transient XRT 210423 and Its Host Galaxy
Bauer, F. E.; Dhillon, V. S.; Littlefair, S. P. +8 more
Fast X-ray Transients (FXTs) are X-ray flares with durations ranging from a few hundred seconds to a few hours. Possible origins include the tidal disruption of a white dwarf by an intermediate-mass black hole, a supernova shock breakout, or a binary neutron star merger. We present the X-ray light curve and spectrum as well as deep optical imaging…
Phase-space Properties and Chemistry of the Sagittarius Stellar Stream Down to the Extremely Metal-poor ([Fe/H] ≲ -3) Regime
Lee, Young Sun; Chiappini, Cristina; Limberg, Guilherme +6 more
In this work, we study the phase-space and chemical properties of the Sagittarius (Sgr) stream, the tidal tails produced by the ongoing destruction of the Sgr dwarf spheroidal (dSph) galaxy, focusing on its very metal-poor (VMP; [Fe/H] < -2) content. We combine spectroscopic and astrometric information from SEGUE and Gaia EDR3, respectively, wi…
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…