Search Publications
On the Rotation of Sunspots and Their Magnetic Polarity
Wang, Haimin; Yang, Zhiliang; Wang, Shuo +2 more
The rotation of sunspots of 2 yr in two different solar cycles is studied with the data from the Helioseismic and Magnetic Imager on board the Solar Dynamics Observatory and the Michelson Doppler Imager instrument on board the Solar and Heliospheric Observataory. We choose the α sunspot groups and the relatively large and stable sunspots of comple…
Fermi-LAT Observations of Supernova Remnant G5.7-0.1, Believed to be Interacting with Molecular Clouds
Slane, Patrick; Castro, Daniel; Gelfand, Joseph +1 more
This work reports on the detection of γ-ray emission coincident with the supernova remnant (SNR) G5.7-0.1 using data collected by the Large Area Telescope on board the Fermi Gamma-ray Space Telescope. The SNR is believed to be interacting with molecular clouds, based on 1720 MHz hydroxyl (OH) maser emission observations in its direction. This inte…
Dense Molecular Cores Being Externally Heated
Kim, Gwanjeong; Kim, Mi-Ryang; Lee, Chang Won +2 more
We present results of our study of eight dense cores, previously classified as starless, using infrared (3-160 µm) imaging observations with the AKARI telescope and molecular line (HCN and N2H+) mapping observations with the KVN telescope. Combining our results with the archival IR to millimeter continuum data, we exami…
An Imaging Study of a Complex Solar Coronal Radio Eruption
Feng, S. W.; Chen, Y.; Song, H. Q. +2 more
Solar coronal radio bursts are enhanced radio emission excited by energetic electrons accelerated during solar eruptions. Studying these bursts is important for investigating the origin and physical mechanism of energetic particles and further diagnosing coronal parameters. Earlier studies suffered from a lack of simultaneous high-quality imaging …
Far-UV Emission Properties of FR1 Radio Galaxies
Danforth, Charles W.; France, Kevin; Stocke, John T. +2 more
The power mechanism and accretion geometry for low-power FR 1 radio galaxies are poorly understood in comparison to those for Seyfert galaxies and QSOs. In this paper, we use the diagnostic power of the Lyα recombination line observed using the Cosmic Origins Spectrograph (COS) aboard the Hubble Space Telescope (HST) to investigate the accretion f…
Obscured AGNs in Bulgeless Hosts discovered by WISE: The Case Study of SDSS J1224+5555
Hickox, R. C.; Secrest, N. J.; Satyapal, S. +6 more
There is mounting evidence that supermassive black holes (SMBHs) form and grow in bulgeless galaxies. However, a robust determination of the fraction of active galactic nuclei (AGNs) in bulgeless galaxies, an important constraint to models of SMBH seed formation and merger-free models of AGN fueling, is unknown, since optical studies have been sho…
Undercover EUV Solar Jets Observed by the Interface Region Imaging Spectrograph
Innes, D. E.; Chen, N. -H.
It is well-known that extreme ultraviolet (EUV) emission emitted at the solar surface is absorbed by overlying cool plasma. Especially in active regions, dark lanes in EUV images suggest that much of the surface activity is obscured. Simultaneous observations from the Interface Region Imaging Spectrograph, consisting of UV spectra and slit-jaw ima…
Contemporaneous Broadband Observations of Three High-redshift BL LAC Objects
Troja, E.; Caraveo, P. A.; Mirabal, N. +101 more
We have collected broadband spectral energy distributions (SEDs) of three BL Lac objects 3FGL J0022.1-1855 (z = 0.689), 3FGL J0630.9-2406 (z\quad ≳ 1.239), and 3FGL J0811.2-7529 (z = 0.774), detected by Fermi with relatively flat gigaelectronvolt spectra. By observing simultaneously in the near-infrared to hard X-ray band, we can well characterize…
Exploring Damped Lyα System Host Galaxies Using Gamma-Ray Bursts
Cenko, S. Bradley; Rafelski, Marc; Veilleux, Sylvain +6 more
We present a sample of 45 Damped Lyα system (DLA; {N}{{H}{{I}}} ≥slant 2× {10}20 {{cm}}-2) counterparts (33 detections, 12 upper limits) which host gamma-ray bursts (GRB-DLAs) in order to investigate star formation and metallicity within galaxies hosting DLAs. Our sample spans z∼ 2{--}6 and is nearly three times la…
Spectroscopy of Luminous Compact Blue Galaxies in Distant Clusters. II. Physical Properties of dE Progenitor Candidates
Randriamampandry, S. M.; Wirth, Gregory D.; Bershady, M. A. +1 more
Luminous Compact Blue Galaxies (LCBGs) are an extreme star-bursting population of galaxies that were far more common at earlier epochs than today. Based on spectroscopic and photometric measurements of LCBGs in massive (M > 1015 M⊙), intermediate redshift (0.5 < z < 0.9) galaxy clusters, we present their rest-frame p…