Search Publications
Spectacular Hubble Space Telescope Observations of the Coma Galaxy D100 and Star Formation in Its Ram Pressure-stripped Tail
Sun, M.; Yagi, M.; Roediger, E. +5 more
We present new HST F275W, F475W, and F814W imaging of the region of the Coma cluster around D100, a spiral galaxy with a remarkably long and narrow (60 × 1.5 kpc) ram pressure-stripped gas tail. We find blue sources coincident with the Hα tail, which we identify as young stars formed in the tail. We also determine they are likely to be unbound ste…
Lifetimes and Emergence/Decay Rates of Star Spots on Solar-type Stars Estimated by Kepler Data in Comparison with Those of Sunspots
Notsu, Yuta; Maehara, Hiroyuki; Namekata, Kosuke +7 more
Active solar-type stars show large quasi-periodic brightness variations caused by stellar rotation with star spots, and the amplitude changes as the spots emerge and decay. The Kepler data are suitable for investigations of the emergence and decay processes of star spots, which are important to understand the underlying stellar dynamo and stellar …
Distinguishing Mergers and Disks in High-redshift Observations of Galaxy Kinematics
Pacifici, Camilla; de la Vega, Alexander; Hayward, Christopher C. +9 more
The majority of massive star-forming galaxies at z ∼ 2 have velocity gradients suggestive of rotation, in addition to large amounts of disordered motions. In this paper, we demonstrate that it is challenging to distinguish the regular rotation of a disk galaxy from the orbital motions of merging galaxies with seeing-limited data. However, the merg…
Massive Dead Galaxies at z ∼ 2 with HST Grism Spectroscopy. I. Star Formation Histories and Metallicity Enrichment
Vulcani, B.; Treu, T.; Jones, T. +7 more
Observations have revealed massive ({log}{M}* /{M}⊙ ≳ 11) galaxies that were already dead when the universe was only ∼2 Gyr. Given the short time before these galaxies were quenched, their past histories and quenching mechanism(s) are of particular interest. In this paper, we study star formation histories (SFHs) of 24 massiv…
Highly Magnified Stars in Lensing Clusters: New Evidence in a Galaxy Lensed by MACS J0416.1-2403
Miralda-Escudé, Jordi; Frye, Brenda; Dai, Liang +2 more
We examine a caustic-straddling arc at z = 0.9397 in the field of the galaxy cluster MACS J0416.1-2403 (z = 0.397) using archival multiband Hubble Space Telescope images and show that its surface brightness exhibits anomalies that can be explained by a single highly magnified star undergoing microlensing. First, we show that the surface brightness…
A New Technique for Finding Galaxies Leaking Lyman-continuum Radiation: [S II]-deficiency
Heckman, Timothy M.; Leitherer, Claus; Wang, Bingjie +3 more
The source responsible for the reionization of the universe is believed to be the population of star-forming galaxies at z ∼ 6 to 12. The biggest uncertainty concerns the fraction of Lyman-continuum photons that actually escape from the galaxies. In recent years, several relatively small samples of “leaky” galaxies have been discovered, and clues …
Merging Cluster Collaboration: A Panchromatic Atlas of Radio Relic Mergers
Bradač, M.; Venturi, T.; Jee, M. J. +13 more
Golovich et al. present an optical imaging and spectroscopic survey of 29 radio relic merging galaxy clusters. In this paper, we study this survey to identify substructure and quantify the dynamics of the mergers. Using a combined photometric and spectroscopic approach, we identify the minimum number of substructures in each system to describe the…
The Polycyclic Aromatic Hydrocarbon Mass Fraction on a 10 pc Scale in the Magellanic Clouds
Gordon, Karl D.; Bot, Caroline; Leroy, Adam K. +8 more
We present maps of the dust properties in the Small and Large Magellanic Clouds (SMC, LMC) from fitting Spitzer and Herschel observations with the Draine & Li dust model. We derive the abundance of the small carbonaceous grain (or polycyclic aromatic hydrocarbon; PAH) component. The global PAH fraction ({q}{{PAH}}, the fraction of t…
ALMA 26 arcmin2 Survey of GOODS-S at 1 mm (ASAGAO): Near-infrared-dark Faint ALMA Sources
Ouchi, Masami; Fujimoto, Seiji; Tamura, Yoichi +21 more
We report detections of two 1.2 mm continuum sources (S 1.2 mm ∼ 0.6 mJy) without any counterparts in the deep H- and/or K-band image (i.e., K-band magnitude ≳26 mag). These near-infrared-dark faint millimeter sources are uncovered by ASAGAO, a deep and wide-field (≃26 arcmin2) Atacama Large Millimeter/submillimeter Array (AL…
The ALMA Discovery of the Rotating Disk and Fast Outflow of Cold Molecular Gas in NGC 1275
Fukazawa, Y.; Nagai, H.; Onishi, K. +13 more
We present observations using the Atacama Large Millimeter/submillimeter Array of the CO(2-1), HCN(3-2), and HCO+(3-2) lines in the nearby radio galaxy/brightest cluster galaxy (BCG) NGC 1275 with a spatial resolution of ∼20 pc. In previous observations, the CO(2-1) emission was detected as radial filaments lying in the east-west direct…