Search Publications
Observational Constraints on Correlated Star Formation and Active Galactic Nuclei in Late-stage Galaxy Mergers
Zakamska, Nadia L.; Comerford, Julia M.; Barrows, R. Scott +1 more
Galaxy mergers are capable of triggering both star formation and active galactic nuclei (AGNs) and therefore may represent an important pathway in the co-evolution of galaxies and supermassive black holes (SMBHs). However, correlated enhancements of merger-induced star formation and AGN triggering may be hidden by the variable conditions and times…
Draining the Local Void
Shaya, Edward J.; Tully, R. Brent; Karachentsev, Igor D. +2 more
Two galaxies that lie deep within the Local Void provide a test of the expectation that voids expand. The modest ({M}B∼ -14) HI bearing dwarf galaxies ALFAZOAJ1952+1428 and KK246 have been imaged with Hubble Space Telescope in order to study the stellar populations and determine distances from the luminosities of stars at the tip of the…
A Nearly Naked Supermassive Black Hole
Darling, Jeremy; Petrov, L.; Condon, J. J. +1 more
During a systematic search for supermassive black holes (SMBHs) not in galactic nuclei, we identified the compact, symmetric radio source B3 1715+425 with an emission-line galaxy offset ≈ 8.5 {kpc} from the nucleus of the brightest cluster galaxy (BCG) in the redshift z = 0.1754 cluster ZwCl 8193. B3 1715+425 is too bright (brightness temperature …
Hub-filament System in IRAS 05480+2545: Young Stellar Cluster and 6.7 GHz Methanol Maser
Dewangan, L. K.; Ojha, D. K.; Baug, T.
To probe the star formation (SF) process, we present a multi-wavelength study of IRAS 05480+2545 (hereafter I05480+2545). Analysis of Herschel data reveals a massive clump (M clump ∼ 1875 {M}⊙ ; peak N(H2) ∼ 4.8 × 1022 cm-2 A V ∼ 51 mag) containing the 6.7 GHz methanol maser and I…
X-Ray Emission from the Nuclear Region of Arp 220
Elvis, Martin; Risaliti, Guido; Karovska, Margarita +6 more
We present an imaging and spectral analysis of the nuclear region of the ultraluminous infrared galaxy merger of Arp 220, using deep Chandra-ACIS observations summing up to ∼ 300 {{ks}}. Narrowband imaging with subpixel resolution of the innermost nuclear region reveals two distinct Fe-K emitting sources, coincident with the infrared and radio nuc…
Sunspots, Starspots, and Elemental Abundances
Doschek, G. A.; Warren, H. P.
Element abundances in the solar photosphere, chromosphere, transition region, and corona are key parameters for investigating sources of the solar wind and for estimating radiative losses in the quiet corona and in dynamical events such as solar flares. Abundances in the solar corona and photosphere differ from each other depending on the first io…
Far-infrared Properties of Infrared-bright Dust-obscured Galaxies Selected with IRAS and AKARI Far-infrared All-sky Survey
Goto, Tomotsugu; Yamamura, Issei; Koyama, Yusei +6 more
We investigate the star-forming activity of a sample of infrared (IR)-bright dust-obscured galaxies (DOGs) that show an extreme red color in the optical and IR regime, {(I-[22])}{AB}> 7.0. Combining an IR-bright DOG sample with the flux at 22 µm > 3.8 mJy discovered by Toba & Nagao with the IRAS faint source catalog vers…
Hot Gas in the Wolf-Rayet Nebula NGC 3199
Gruendl, R. A.; Marston, A. P.; Chu, Y. -H. +2 more
The Wolf-Rayet (WR) nebula NGC 3199 has been suggested to be a bow shock around its central star, WR 18, which is presumably a runaway star, because optical images of the nebula show a dominating arc of emission southwest of the star. We present the XMM-Newton detection of extended X-ray emission from NGC 3199, unveiling the powerful effect of the…
Modeling Type II-P/II-L Supernovae Interacting with Recent Episodic Mass Ejections from Their Presupernova Stars with MESA and SNEC
Das, Sanskriti; Ray, Alak
We show how dense, compact, discrete shells of circumstellar gas immediately outside of red supergiants affect the optical light curves of Type II-P/II-L supernovae (SNe), using the example of SN 2013ej. Earlier efforts in the literature had used an artificial circumstellar medium (CSM) stitched to the surface of an evolved star that had not gone …
The Evolution of Star formation Activity in Cluster Galaxies over 0.15 < z < 1.5
Stanford, S. A.; Stern, Daniel; Snyder, Gregory F. +3 more
We explore 7.5 billion years of evolution in the star formation activity of massive ({M}\star > {10}10.1 {M}⊙ ) cluster galaxies using a sample of 25 clusters over 0.15< z< 1 from the Cluster Lensing And Supernova survey with Hubble and 11 clusters over 1< z< 1.5 from the IRAC Shallow Cluster Survey.…