Search Publications
Extended and filamentary Lyα emission from the formation of a protogalactic halo at z = 2.63
Rauch, Michael; Haehnelt, Martin G.; Sargent, Wallace L. W. +2 more
We report the observation of a further asymmetric, extended Lyα emitting halo at z = 2.63, from our ultra-deep, long-slit spectroscopic survey of faint high-redshift emitters, undertaken with Magellan LDSS3 in the GOODS-S field. The Lyα emission, detected over more than 30 kpc, is spatially coincident with a statistically significant concentration…
Discovery of a Giant Radio Halo in a New Planck Galaxy Cluster PLCKG171.9-40.7
Wik, Daniel R.; Giacintucci, Simona; Venturi, Tiziana +2 more
We report the discovery of a giant radio halo in a new, hot, X-ray luminous galaxy cluster recently found by Planck, PLCKG171.9-40.7. The radio halo was found using Giant Metrewave Radio Telescope observations at 235 MHz and 610 MHz, and in the 1.4 GHz data from an NRAO Very Large Array Sky Survey pointing that we have reanalyzed. The diffuse radi…
A Search for Rapidly Accreting White Dwarfs in the Small Magellanic Cloud
Lepo, Kelly; van Kerkwijk, Marten
The nature of the progenitors of Type Ia supernovae (SNe Ia) is still a mystery. While plausible candidates are known for both the single-degenerate and double-degenerate models, the observed numbers fall significantly short of what is required to reproduce the SNe Ia rate. Some of the most promising single-degenerate Type Ia progenitors are recur…
The 2011 Periastron Passage of the Be Binary δ Scorpii
Okazaki, A. T.; Miroshnichenko, A. S.; Pasechnik, A. V. +19 more
We describe the results of the world-wide observing campaign of the highly eccentric Be binary system δ Scorpii 2011 periastron passage which involved professional and amateur astronomers. Our spectroscopic observations provided a precise measurement of the system orbital period at 10.8092 ± 0.0005 yr. Fitting of the He II 4686 Å line radial veloc…
Inner rings in disc galaxies: dead or alive
Comerón, S.
In this Letter, I distinguish "passive" inner rings as those with no current star formation as distinct from "active" inner rings that have undergone recent star formation. I built a sample of nearby galaxies with inner rings observed in the near- and mid-infrared from the NIRS0S and the S4G surveys. I used archival far-ultraviolet (FUV…
Synergistic observations of Io’s atmosphere in 2010 from HST-COS in the mid-ultraviolet and IRTF-TEXES in the mid-infrared
Tsang, Constantine C. C.; Spencer, John R.; Jessup, Kandis Lea
We report on mid-UV spectroscopy of Io’s SO2 atmosphere from the Cosmic Origins Spectrograph (COS) on the Hubble Space Telescope (HST), and compare to contemporaneous ground-based mid-infrared spectroscopy of the atmosphere. Our motivation is to evaluate the consistency of atmospheric parameters derived by different observational techni…
Multiwavelength Astronomy and CTA: X-rays
Takahashi, Tadayuki; Uchiyama, Yasunobu; Stawarz, Łukasz
We discuss how future X-ray instruments which are under development can contribute to our understanding of the non-thermal Universe. Much progress has been made in the field of X-ray Astronomy recently, thanks to the operation of modern X-ray telescopes such as Chandra, XMM-Newton, Suzaku, and SWIFT, but more in-depth investigation awaits future m…
The Hohmann-Parker effect measured by the Mars Science Laboratory on the transfer from Earth to Mars: Consequences and opportunities
Frahm, R. A.; Wimmer-Schweingruber, R. F.; Christian, E. R. +33 more
We show that a spacecraft launched from Earth towards Mars following a Hohmann minimum energy transfer trajectory has a strong tendency to remain well-connected magnetically to Earth, in the early phase of the transfer, or to Mars in the late phase, via the Parker spiral magnetic field. On the return trip, the spacecraft would remain reasonably we…
The astrophysics of the intracluster plasma
Lapi, Andrea; Cavaliere, Alfonso
Since 1971 observations in X rays of several thousands of galaxy clusters have uncovered huge amounts of hot baryons filling up the deep gravitational potential wells provided by dark matter (DM) halos with masses of some 1015 M⊙ and sizes of millions of light-years. At temperatures T∼108 K and with average densiti…
New Suns in the Cosmos?
Catelan, M.; Ferreira Lopes, C. E.; De Medeiros, J. R. +5 more
The present work reports on the discovery of three stars that we have identified to be rotating Sun-like stars, based on rotational modulation signatures inferred from light curves from the CoRoT mission's Public Archives. In our analysis, we performed an initial selection based on the rotation period and position in the period-T eff di…