Search Publications
An Ultraviolet Survey of Low-redshift Partial Lyman-limit Systems with the HST Cosmic Origins Spectrograph
Stevans, Matthew L.; Shull, J. Michael; Danforth, Charles W. +2 more
We present an ultraviolet spectroscopic survey of strong H I absorbers in the intergalactic medium, probing their evolution over the last 6-7 Gyr at redshifts 0.24 ≤ z ≤ 0.84. We measure column densities N H I (cm-2) from the pattern of Lyman-series absorption lines and flux decrement at the Lyman limit (LL) when available. …
Magnetic Flux Rope Shredding By a Hyperbolic Flux Tube: The Detrimental Effects of Magnetic Topology on Solar Eruptions
Vourlidas, Angelos; Stenborg, Guillermo; Chintzoglou, Georgios +3 more
We present the analysis of an unusual failed eruption captured in high cadence and in many wavelengths during the observing campaign in support of the Very high Angular resolution Ultraviolet Telescope (VAULT2.0) sounding rocket launch. The refurbished VAULT2.0 is a Lyα (λ 1216 Å) spectroheliograph launched on 2014 September 30. The campaign targe…
A Universal Correlation between Star Formation Activity and Molecular Gas Properties Across Environments
Nakagawa, Takao; Suzuki, Tomoko L.; Koyama, Yusei +10 more
We present the molecular gas mass fraction ({f}{{{H}}2}) and star formation efficiency (SFE) of local galaxies on the basis of our new CO(J=1-0) observations with the Nobeyama 45 m radio telescope, combined with the COLDGASS galaxy catalog, as a function of galaxy environment defined as the local number density of galaxies me…
NuSTAR Hard X-Ray Observations of the Energetic Millisecond Pulsars PSR B1821-24, PSR B1937+21, and PSR J0218+4232
Gotthelf, E. V.; Bogdanov, S.
We present Nuclear Spectroscopic Telescope Array (NuSTAR) hard X-ray timing and spectroscopy of the three exceptionally energetic rotation-powered millisecond pulsars PSRs B1821-24, B1937+21, and J0218+4232. By correcting for the frequency and phase drifts of the NuSTAR onboard clock, we are able to recover the intrinsic hard X-ray pulse profiles …
Measure the Propagation of a Halo CME and Its Driven Shock with the Observations from a Single Perspective at Earth
Feng, Li; Lu, Lei; Inhester, Bernd +2 more
We present a detailed study of an Earth-directed coronal mass ejection (full-halo CME) event that happened on 2011 February 15, making use of white-light observations by three coronagraphs and radio observations by Wind/WAVES. We applied three different methods to reconstruct the propagation direction and traveling distance of the CME and its driv…
Multi-wavelength Spectral Analysis of Ellerman Bombs Observed by FISS and IRIS
Cao, Wenda; Ding, M. D.; Hong, Jie
Ellerman bombs (EBs) are a kind of solar activity that is suggested to occur in the lower solar atmosphere. Recent observations using the Interface Region Imaging Spectrograph (IRIS) show connections between EBs and IRIS bombs (IBs), which imply that EBs might be heated to a much higher temperature (8 × 104 K) than previous results. Her…
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…