Search Publications
Cleaning Our Hazy Lens: Exploring Trends in Transmission Spectra of Warm Exoplanets
Fortney, Jonathan J.; Zhang, Xi; Thorngren, Daniel +4 more
Relatively little is understood about the atmospheric composition of temperate to warm exoplanets (equilibrium temperature T eq < 1000 K), as many of them are found to have uncharacteristically flat transmission spectra. Their flattened spectra are likely due to atmospheric opacity sources such as planet-wide photochemical hazes and …
From Naked Spheroids to Disky Galaxies: How Do Massive Disk Galaxies Shape Their Morphology?
Barro, Guillermo; Pérez-González, Pablo G.; Costantin, Luca +9 more
We investigate the assembly history of massive disk galaxies and describe how they shape their morphology through cosmic time. Using SHARDS and HST data, we modeled the surface brightness distribution of 91 massive galaxies at redshift 0.14 < z ≤ 1 in the wavelength range 0.5-1.6 µm, deriving the uncontaminated spectral energy distributio…
Modelling the water and carbon dioxide production rates of Comet 67P/Churyumov-Gerasimenko
Samarasinha, Nalin H.; Farnocchia, Davide; Gutiérrez, Pedro J. +1 more
The European Space Agency Rosetta/Philae mission to Comet 67P/Churyumov-Gerasimenko in 2014-2016 is the most complete and diverse investigation of a comet carried out thus far. Yet, many physical and chemical properties of the comet remain uncertain or unknown, and cometary activity is still not a well-understood phenomenon. We here attempt to pla…
The chemical composition of globular clusters in the Local Group
Larsen, S. S.; Strader, J.; Bergemann, M. +5 more
We present detailed chemical abundance measurements for 45 globular clusters (GCs) associated with galaxies in (and, in one case, beyond) the Local Group. The measurements are based on new high-resolution integrated-light spectra of GCs in the galaxies NGC 185, NGC 205, M 31, M 33, and NGC 2403, combined with reanalysis of previously published obs…
About Metallicity Variations in the Local Galactic Interstellar Medium
Méndez-Delgado, J. E.; Arellano-Córdova, K. Z.; García-Rojas, J. +1 more
In this paper we discuss and confront recent results on metallicity variations in the local interstellar medium, obtained from observations of H II regions and neutral clouds of the Galactic thin disk, and compare them with recent high-quality metallicity determinations of other tracers of the chemical composition of the interstellar medium as B-t…
Measurements of the Hubble Constant with a Two-rung Distance Ladder: Two Out of Three Ain't Bad
Casertano, Stefano; Jones, David O.; Riess, Adam G. +7 more
The three-rung distance ladder, which calibrates Type Ia supernovae (SNe Ia) through stellar distances linked to geometric measurements, provides the highest precision direct measurement of the Hubble constant. In light of the Hubble tension, it is important to test the individual components of the distance ladder. For this purpose, we report a me…
New LZ and PW(Z) relations of RR Lyrae stars calibrated with Gaia EDR3 parallaxes
Sarro, L. M.; Clementini, G.; Ripepi, V. +4 more
We present new luminosity-metallicity (LZ; $M_{V}\!-\!\rm [Fe/H]$ and $M_{G}\!-\!\rm [Fe/H]$) relations and, for the first time, empirical, Gaia three-band (G, GBP, GRP) period-Wesenheit-metallicity (PWZ) relations of RR Lyrae stars (RRLs) derived using a hierarchical Bayesian approach and new accurate parallaxes published fo…
Birth of a Be star: an APOGEE search for Be stars forming through binary mass transfer
Conroy, Charlie; Stassun, Keivan G.; Cargile, Phillip +7 more
Motivated by recent suggestions that many Be stars form through binary mass transfer, we searched the APOGEE survey for Be stars with bloated, stripped companions. From a well-defined parent sample of 297 Be stars, we identified one mass-transfer binary, HD 15124. The object consists of a main-sequence Be star ($M_{\rm Be}=5.3\pm 0.6\, {\rm M}_{\o…
Early Results from GLASS-JWST. VIII. An Extremely Magnified Blue Supergiant Star at Redshift 2.65 in the A2744 Cluster Field
Castellano, Marco; Treu, Tommaso; Frye, Brenda L. +18 more
We report the discovery of an extremely magnified star at redshift z = 2.65 in the James Webb Space Telescope (JWST) NIRISS pre-imaging of the A2744 galaxy-cluster field. The star's background host galaxy lies on a fold caustic of the foreground lens, and the cluster creates a pair of images of the region close to the lensed star. We identified th…
AU Microscopii in the Far-UV: Observations in Quiescence, during Flares, and Implications for AU Mic b and c
France, Kevin; Youngblood, Allison; Gaidos, Eric +13 more
High-energy X-ray and ultraviolet (UV) radiation from young stars impacts planetary atmospheric chemistry and mass loss. The active ~22 Myr M dwarf AU Mic hosts two exoplanets orbiting interior to its debris disk. Therefore, this system provides a unique opportunity to quantify the effects of stellar X-ray and UV irradiation on planetary atmospher…