Search Publications
On the Temporal Evolution of Spicules Observed with IRIS, SDO, and Hinode
De Pontieu, B.; Rouppe van der Voort, L.; Pereira, T. M. D. +1 more
Spicules are ubiquitous, fast moving jets observed off-limb in chromospheric spectral lines. Combining the recently launched Interface Region Imaging Spectrograph with the Solar Dynamics Observatory and Hinode, we have a unique opportunity to study spicules simultaneously in multiple passbands and from a seeing free environment. This makes it poss…
Type IIb Supernova 2013df Entering into an Interaction Phase: A Link between the Progenitor and the Mass Loss
Folatelli, G.; Tanaka, M.; Phillips, M. M. +23 more
We report the late-time evolution of Type IIb supernova (SN IIb) 2013df. SN 2013df showed a dramatic change in its spectral features at ∼1 yr after the explosion. Early on it showed typical characteristics shared by SNe IIb/Ib/Ic dominated by metal emission lines, while later on it was dominated by broad and flat-topped Hα and He i emissions. The …
Hubble Tarantula Treasury Project. II. The Star-formation History of the Starburst Region NGC 2070 in 30 Doradus
Anderson, J.; Zaritsky, D.; Lennon, D. J. +10 more
We present a study of the recent star formation (SF) of 30 Doradus in the Large Magellanic Cloud (LMC) using the panchromatic imaging survey Hubble Tarantula Treasury Project. In this paper we focus on the stars within 20 pc of the center of 30 Doradus, the starburst region NGC 2070. We recovered the SF history by comparing deep optical and near-i…
Discovery of a Strongly Lensed Massive Quiescent Galaxy at z = 2.636: Spatially Resolved Spectroscopy and Indications of Rotation
Ellis, Richard S.; Belli, Sirio; Newman, Andrew B.
We report the discovery of RG1M0150, a massive, recently quenched galaxy at z = 2.636 that is multiply imaged by the cluster MACSJ0150.3-1005. We derive a stellar mass of {log}{M}*={11.49}-0.16+0.10 and a half-light radius of {R}e,{maj}=1.8+/- 0.4 {{kpc}}. Taking advantage of the lensing magnification, w…
Correlation between Galaxy Mergers and Luminous Active Galactic Nuclei
Ho, Luis C.; Im, Myungshin; Kim, Minjin +1 more
It is not yet clear what triggers the activity of active galactic nuclei (AGNs), but galaxy merging has been suspected to be one of the main mechanisms fueling the activity. Using deep optical images taken at various ground-based telescopes, we investigate the fraction of galaxy mergers in 39 luminous AGNs (MR ≲ -22.6 mag) at z ≤ 0.3 (a…
X-Ray and EUV Observations of Simultaneous Short and Long Period Oscillations in Hot Coronal Arcade Loops
Kumar, Pankaj; Cho, Kyung-Suk; Nakariakov, Valery M.
We report decaying quasi-periodic intensity oscillations in the X-ray (6-12 keV) and extreme-ultraviolet (EUV) channels (131, 94, 1600, 304 Å) observed by the Fermi Gamma-ray Burst Monitor and Solar Dynamics Observatory/Atmospheric Imaging Assembly (AIA), respectively, during a C-class flare. The estimated periods of oscillation and decay time in …
Magnetic Structure and Dynamics of the Erupting Solar Polar Crown Prominence on 2012 March 12
Reeves, Katharine K.; van Ballegooijen, Adriaan; DeLuca, Edward E. +3 more
We present an investigation of the polar crown prominence that erupted on 2012 March 12. This prominence is observed at the southeast limb by the Solar Dynamics Observatory (SDO)/Atmospheric Imaging Assembly (AIA; end-on view) and displays a quasi-vertical thread structure. A bright U-shaped or horn-like structure is observed surrounding the upper…
NuSTAR Reveals Extreme Absorption in z < 0.5 Type 2 Quasars
Harrison, F. A.; Stern, D.; Zhang, W. W. +27 more
The intrinsic column density (NH) distribution of quasars is poorly known. At the high obscuration end of the quasar population and for redshifts z < 1, the X-ray spectra can only be reliably characterized using broad-band measurements that extend to energies above 10 keV. Using the hard X-ray observatory NuSTAR, along with archival …
Determination of the Mass of IGR J17091-3624 from "Spectro-temporal" Variations during the Onset Phase of the 2011 Outburst
Nandi, A.; Mandal, S.; Iyer, N.
The 2011 outburst of the black hole candidate IGR J17091-3624 followed the canonical track of state transitions along with the evolution of quasi-periodic oscillation (QPO) frequencies before it began exhibiting various variability classes similar to GRS 1915+105. We use this canonical evolution of spectral and temporal properties to determine the…
The Spatial Distribution of the Young Stellar Clusters in the Star-forming Galaxy NGC 628
Cignoni, M.; Dale, D. A.; Calzetti, D. +21 more
We present a study of the spatial distribution of the stellar cluster populations in the star-forming galaxy NGC 628. Using Hubble Space Telescope broadband WFC3/UVIS UV and optical images from the Treasury Program LEGUS (Legacy ExtraGalactic UV Survey), we have identified 1392 potential young (≲ 100 Myr) stellar clusters within the galaxy using a…