Search Publications
Gas Sloshing Regulates and Records the Evolution of the Fornax Cluster
Jones, Christine; Nulsen, Paul E. J.; Kraft, Ralph P. +7 more
We present results of a joint Chandra and XMM-Newton analysis of the Fornax Cluster, the nearest galaxy cluster in the southern sky. Signatures of merger-induced gas sloshing can be seen in the X-ray image. We identify four sloshing cold fronts in the intracluster medium, residing at radii of 3 kpc (west), 10 kpc (northeast), 30 kpc (southwest), a…
Dust Abundance Variations in the Magellanic Clouds: Probing the Life-cycle of Metals with All-sky Surveys
Bot, Caroline; Roman-Duval, Julia; Gordon, Karl +1 more
Observations and modeling suggest that dust abundance (gas-to-dust ratio, G/D) depends on (surface) density. Variations of the G/D provide timescale constraints for the different processes involved in the life cycle of metals in galaxies. Recent G/D measurements based on Herschel data suggest a factor of 5-10 decrease in dust abundance between the…
The HDUV Survey: Six Lyman Continuum Emitter Candidates at z ∼ 2 Revealed by HST UV Imaging
Oesch, P. A.; Carollo, C. M.; Nelson, E. J. +14 more
We present six galaxies at z∼ 2 that show evidence of Lyman continuum (LyC) emission based on the newly acquired UV imaging of the Hubble Deep UV legacy survey (HDUV) conducted with the WFC3/UVIS camera on the Hubble Space Telescope (HST). At the redshift of these sources, the HDUV F275W images partially probe the ionizing continuum. By exploiting…
Formation of Methylamine and Ethylamine in Extraterrestrial Ices and Their Role as Fundamental Building Blocks of Proteinogenic α-amino Acids
Kaiser, Ralf I.; Förstel, Marko; Bergantini, Alexandre +2 more
The -CH-NH2 moiety represents the fundamental building block of all proteinogenic amino acids, with the cyclic amino acid proline being a special case (-CH-NH- in proline). Exploiting a chemical retrosynthesis, we reveal that methylamine (CH3NH2) and/or ethylamine (CH3CH2NH2) are es…
A Surface Density Perturbation in the TW Hydrae Disk at 95 au Traced by Molecular Emission
Henning, Th.; van Boekel, R.; Birnstiel, T. +6 more
We present ALMA Cycle 2 observations at 0.″5 resolution of TW Hya of CS J=5-4 emission. The radial profile of the integrated line emission displays oscillatory features outward of 1.″5 (≈ 90 au). A dip-like feature at 1.″6 is coincident in location, depth, and width with features observed in dust scattered light at near-infrared wavelengths. Using…
Optical Line Emission from z ∼ 6.8 Sources with Deep Constraints on Lyα Visibility
Maiolino, R.; Finkelstein, S. L.; Castellano, M. +15 more
We analyze a sample of z-dropout galaxies in the CANDELS GOODS South and UDS fields that have been targeted by a dedicated spectroscopic campaign aimed at detecting their Lyα line. Deep IRAC observations at 3.6 and 4.5 µm are used to determine the strength of optical emission lines affecting these bands at z ∼ 6.5-6.9 in order to (1) investi…
Chemical Cartography. I. A Carbonicity Map of the Galactic Halo
Yoon, Jinmi; Beers, Timothy C.; Lee, Young Sun +5 more
We present the first map of carbonicity, [C/Fe], for the halo system of the Milky Way, based on a sample of over 100,000 main-sequence turnoff stars with available spectroscopy from the Sloan Digital Sky Survey. This map, which explores distances up to 15 kpc from the Sun, reveals clear evidence for the dual nature of the Galactic halo, based on t…
η Carinae's Dusty Homunculus Nebula from Near-infrared to Submillimeter Wavelengths: Mass, Composition, and Evidence for Fading Opacity
Hillier, D. John; Gull, Theodore R.; Nielsen, Krister +5 more
Infrared observations of the dusty, massive Homunculus Nebula around the luminous blue variable η Carinae are crucial to characterize the mass-loss history and help constrain the mechanisms leading to the great eruption. We present the 2.4-670 µm spectral energy distribution, constructed from legacy Infrared Space Observatory observations an…
AGN Coronae through a Jet Perspective
Kara, Erin; Lohfink, Anne; King, Ashley L.
This paper presents an in-depth look at the jet and coronal properties of 41 active galactic nuclei (AGNs). Utilizing the highest quality NuSTAR, XMM-Newton, and NRAO VLA Sky Survey 1.4 GHz data, we find that the radio Eddington luminosity inversely scales with X-ray reflection fraction, and positively scales with the distance between the corona a…
Extending the Calibration of C IV-based Single-epoch Black Hole Mass Estimators for Active Galactic Nuclei
Treu, Tommaso; Barth, Aaron J.; Assef, Roberto J. +5 more
We provide an updated calibration of C IV λ 1549 broad emission line-based single-epoch (SE) black hole (BH) mass estimators for active galactic nuclei (AGNs) using new data for six reverberation-mapped AGNs at redshift z=0.005{--}0.028 with BH masses (bolometric luminosities) in the range {10}6.5{--}{10}7.5 {M}⊙ …