Search Publications
Stellar haloes of disc galaxies at z ∼ 1
Trujillo, Ignacio; Bakos, Judit
Taking advantage of the ultradeep near-infrared imaging obtained with the Hubble Space Telescope on the Hubble Ultra Deep Field, we detect and explore for the first time the properties of the stellar haloes of two Milky Way-like galaxies at z ∼ 1. We find that the structural properties of those haloes (size and shape) are similar to the ones found…
Deep Chandra Observations of A2199: The Interplay between Merger-induced Gas Motions and Nuclear Outbursts in a Cool Core Cluster
Fabian, Andrew C.; Sanders, Jeremy S.; Churazov, Eugene +9 more
We present new Chandra observations of A2199 that show evidence of gas sloshing due to a minor merger, as well as impacts of the radio source, 3C 338, hosted by the central galaxy, NGC 6166, on the intracluster gas. The new data are consistent with previous evidence of a Mach ~= 1.46 shock 100'' from the cluster center, although there is still no …
On the Radii of Brown Dwarfs Measured with AKARI Near-infrared Spectroscopy
Murakami, H.; Yamamura, I.; Sorahana, S.
We derive the radii of 16 brown dwarfs observed by AKARI using their parallaxes and the ratios of observed to model fluxes. We find that the brown dwarf radius ranges between 0.64-1.13 RJ with an average radius of 0.83 RJ . We find a trend in the relation between radii and T eff; the radius is at a minimum at T
A Relation of the PAH 3.3 µm Feature with Star-forming Activity for Galaxies with a Wide Range of Infrared Luminosity
Oyabu, Shinki; Yamagishi, Mitsuyoshi; Im, Myungshin +4 more
For star-forming galaxies, we investigated a global relation between the polycyclic aromatic hydrocarbon (PAH) emission luminosity at 3.3 µm, LPAH3.3, and the infrared (8-1000 µm) luminosity, LIR, to understand how the PAH 3.3 µm feature relates to star-formation activity. With AKARI, we performed near-infra…
Multi-instrument observations from Svalbard of a traveling convection vortex, electromagnetic ion cyclotron wave burst, and proton precipitation associated with a bow shock instability
Lavraud, B.; Yeoman, T. K.; Clausen, L. B. N. +12 more
An isolated burst of 0.35 Hz electromagnetic ion cyclotron (EMIC) waves was observed at four sites on Svalbard from 0947 to 0954 UT 2 January 2011, roughly 1 h after local noon. This burst was associated with one of a series of ~50 nT magnetic impulses observed at the northernmost stations of the IMAGE magnetometer array. Hankasalmi SuperDARN rada…
The Ultraluminous GRB 110918A
Zhang, X.; Sbarufatti, B.; Hurley, K. +29 more
GRB 110918A is the brightest long gamma-ray burst (GRB) detected by Konus-WIND during its almost 19 yr of continuous observations and the most luminous GRB ever observed since the beginning of the cosmological era in 1997. We report on the final Interplanetary Network localization of this event and its detailed multiwavelength study with a number …
Overlying Extreme-ultraviolet Arcades Preventing Eruption of a Filament Observed by AIA/SDO
Zhang, Jun; Chen, Huadong; Ma, Suli
Using the multi-wavelength data from the Atmospheric Imaging Assembly/Solar Dynamic Observatory (AIA/SDO) and the Sun Earth Connection Coronal and Heliospheric Investigation/Solar Terrestrial Relations Observatory (SECCHI/STEREO), we report a failed filament eruption in NOAA AR 11339 on 2011 November 3. The eruption was associated with an X1.9 fla…
Simultaneous conjugate observations of small-scale structures in Saturn's dayside ultraviolet auroras: Implications for physical origins
Yeoman, T. K.; Nichols, J. D.; Cowley, S. W. H. +2 more
Small-scale features in Saturn's dayside UV auroras are examined using images obtained on 32 Hubble Space Telescope visits close to Saturn equinox when both northern and southern emissions were simultaneously observed, allowing their interhemispheric conjugacy to be investigated. Eastward-propagating patches in the dawn-to-noon sector were observe…
Nebular spectroscopy of the nearby Type IIb supernova 2011dh
Van Dyk, Schuyler D.; Filippenko, Alexei V.; Cenko, S. Bradley +6 more
We present nebular spectra of the nearby Type IIb supernova (SN) 2011dh taken between 201 and 678 d after core collapse. At these late times, SN 2011dh exhibits strong emission lines including a broad and persistent Hα feature. New models of the nebular spectra confirm that the progenitor of SN 2011dh was a low-mass giant (M ≈ 13-15 M⊙)…
Metallicity Effect on Low-mass X-Ray Binary Formation in Globular Clusters
Ivanova, N.; Fabbiano, G.; Sivakoff, G. R. +4 more
We present comprehensive observational results of the metallicity effect on the fraction of globular clusters (GCs) that contain low-mass X-ray binaries (LMXB), by utilizing all available data obtained with Chandra for LMXBs and Hubble Space Telescope Advanced Camera for Surveys (ACS) for GCs. Our primary sample consists of old elliptical galaxies…