Search Publications
Suzaku observations of the galaxy cluster 1RXS J0603.3+4214: Implications of particle acceleration processes in the "Toothbrush" radio relic
Ohashi, Takaya; Takizawa, Motokazu; Akamatsu, Hiroki +4 more
We present the results of Suzaku observations of the galaxy cluster 1RXS J0603.3+4214 with the "Toothbrush" radio relic. Although a shock with Mach number M ≃ 4 is expected at the outer edge of the relic from the radio observation, our temperature measurements of the intracluster medium indicate a weaker temperature difference than expected. The M…
The impact of strong gravitational lensing on observed Lyman-break galaxy numbers at 4 ≤ z ≤ 8 in the GOODS and the XDF blank fields
Treu, T.; Trenti, M.; Illingworth, G. D. +5 more
Detections of Lyman-break galaxies (LBGs) at high-redshift are affected by gravitational lensing induced by foreground deflectors not only in galaxy clusters, but also in blank fields. We quantify the impact of strong magnification in the samples of B435, V606, i775 and z850 & Y105 dropout…
M 101 group galaxies
Tikhonov, N. A.; Galazutdinova, O. A.; Lebedev, V. S.
Based on archival Hubble Space Telescope images, we have performed stellar photometry for the galaxy M 101 and other neighboring galaxies located at a small angular distance from M 101 and having radial velocities similar to that of M 101: M 51, M 63, NGC 5474, NGC 5477, UGC 9405, Ho IV, KUG1413+573, and others. Based on the TRGB method, we have d…
The NuSTAR X-ray spectrum of the low-luminosity active galactic nucleus in NGC 7213
Harrison, F. A.; Stern, D.; Bauer, F. E. +11 more
We present an analysis of the 3-79 keV NuSTAR spectrum of the low-luminosity active galactic nucleus NGC 7213. In agreement with past observations, we find a lower limit to the high-energy cut-off of Ec > 140 keV, no evidence for a Compton-reflected continuum and the presence of an iron K α complex, possibly produced in the broad-lin…
Eta Carinae's 2014.6 spectroscopic event: Clues to the long-term recovery from its Great Eruption
Weis, K.; Davidson, K.; Humphreys, R. M. +9 more
Aims: Every 5.5 years, η Car's light curve and spectrum change remarkably across all observed wavelength bands. These so-called spectroscopic events are most likely caused by the close approach of a companion. We compare the recent spectroscopic event in mid-2014 to the events in 2003 and 2009 and investigate long-term trends.
Methods: E…
Evidence of the Ion Cyclotron Resonance at Proton Kinetic Scales in the Solar Wind
Li, Xing; Roberts, O. W.
The k-filtering and wave polarization techniques are applied to Cluster magnetic field data at four intervals of fast free (not connected to Earth's foreshock) solar wind. In addition to the commonly observed population of magnetic field fluctuations propagating at quasi-perpendicular angles to the global mean field B0 , a population of…
Probing the MSP Prenatal Stage: The Optical Identification of the X-Ray Burster EXO 1745-248 in Terzan 5
Dalessandro, E.; Massari, D.; Mucciarelli, A. +4 more
We report on the optical identification of the neutron star burster EXO 1745-248 in Terzan 5. The identification was performed by exploiting Hubble Space Telescope/Advanced Camera for Surveys images acquired in Director's Discretionary Time shortly after (approximately one month) the Swift detection of the X-ray burst. The comparison between these…
J021659-044920: a relic giant radio galaxy at z ∼ 1.3
Beelen, A.; Singh, V.; Ishwara-Chandra, C. H. +4 more
We report the discovery of a relic Giant Radio Galaxy (GRG) J021659-044920 at redshift z ∼ 1.3 that exhibits large-scale extended, nearly co-spatial, radio and X-ray emission from radio lobes, but no detection of Active Galactic Nuclei core, jets and hotspots. The total angular extent of the GRG at the observed frame 0.325 GHz, using Giant Metrewa…
Extensive Middle Amazonian mantling of debris aprons and plains in Deuteronilus Mensae, Mars: Implications for the record of mid-latitude glaciation
Head, James W.; Baker, David M. H.
The mid-latitudes of Mars are host to a record of recent episodes of accumulations of ice-rich materials. The record includes debris aprons, interpreted to be debris-covered glaciers, that may represent the preserved remnants of a much more extensive ice sheet. We assessed the possibility of former glacial extents by examining debris aprons and th…
Constraining star formation rates in cool-core brightest cluster galaxies
Combes, Françoise; Mittal, Rupal; Whelan, John T.
We used broad-band imaging data for 10 cool-core brightest cluster galaxies (BCGs) and conducted a Bayesian analysis using stellar population synthesis to determine the likely properties of the constituent stellar populations. Determination of ongoing star formation rates (SFRs), in particular, has a direct impact on our understanding of the cooli…