Search Publications

Suzaku Observations of Subhalos in the Coma Cluster

Sato, Kosuke; Okabe, Nobuhiro; Matsushita, Kyoko +1 more

We observed three massive subhalos in the Coma cluster with Suzaku. These subhalos, labeled “ID 1,” “ID 2,” and “ID 32,” were detected with a weak-lensing survey using Subaru/Suprime-Cam, and are located at the projected distances of 1.4 r₅₀₀, 1.2 r₅₀₀, and 1.6 r₅₀₀ from the center of the Coma cluster, respectively…

The capabilities of ROSINA/DFMS to measure argon isotopes at comet 67P/Churyumov-Gerasimenko

Altwegg, K.; Berthelier, J. J.; Fuselier, S. A. +8 more

Little is known about the noble gas abundances in comets. These highly volatile atoms are possible tracers of the history of cometary matter including the thermal evolution. They can help quantify the contribution of cometary impacts to terrestrial oceans and help elucidate on the formation history of comets and their role in the formation and evo…

Constraints on the evolutionary mechanisms of massive galaxies since z ∼ 1 from their velocity dispersions

Pérez-González, P. G.; Falcón-Barroso, J.; Guzmán, R. +9 more

Several authors have reported that the dynamical masses of massive compact galaxies (M_* ≳ 10¹¹ M_⊙, r_e ∼ 1 kpc), computed as M_dyn = 5.0 σ_e² r_e/G, are lower than their stellar masses M_*. In a previous study from our group, the discrepancy is interprete…

Pluto and Charon's UV spectra from IUE to New Horizons

Stern, S. Alan; Schindhelm, Rebecca; Gladstone, Randy +1 more

We compare Mid-Ultraviolet (MUV) spectra of Pluto taken over a period of 20 years by the International Ultraviolet Explorer, the HST-Faint Object Spectrograph, and the HST-Cosmic Origins Spectrograph. We extract Pluto-only spectra from the IUE data and associate them with corrected longitudes when necessary. Comparing them with HST spectra provide…

The Importance of Long-Term Synoptic Observations and Data Sets for Solar Physics and Helioseismology

Gosain, Sanjay; Broomhall, Anne-Marie; Elsworth, Yvonne +3 more

A casual single glance at the Sun would not lead an observer to conclude that it varies. The discovery of the 11-year sunspot cycle was only made possible through systematic daily observations of the Sun over 150 years and even today historic sunspot drawings are used to study the behavior of past solar cycles. The origin of solar activity is stil…

Deep X-ray spectroscopy and imaging of the Seyfert 2 galaxy, ESO 138-G001

Bianchi, S.; Vignali, C.; Piconcelli, E. +4 more

We present a spectral and imaging analysis of the XMM-Newton and Chandra observations of the Seyfert 2 galaxy ESO138-G001, with the aim of characterizing the circumnuclear material responsible for the soft (0.3-2.0 keV) and hard (5-10 keV) X-ray emission. We confirm that the source is absorbed by Compton-thick gas. However, if a self-consistent mo…

A spectroscopically confirmed z = 1.327 galaxy-scale deflector magnifying a z ∼ 8 Lyman-break galaxy in the Brightest of Reionizing Galaxies survey

Treu, T.; Trenti, M.; Oesch, P. A. +6 more

We present a detailed analysis of an individual case of gravitational lensing of a z ∼ 8 Lyman-break galaxy (LBG) in a blank field, identified in Hubble Space Telescope imaging obtained as part of the Brightest of Reionizing Galaxies survey. To investigate the close proximity of the bright (m_AB = 25.8) Y₀₉₈-dropout to a small…

Testing isotropy of cosmos with WMAP and PLANCK data

Rath, Pranati K.; Samal, Pramoda Kumar

In recent years, there have been a large number of studies which support violation of statistical isotropy. Meanwhile, there are some studies which also found inconsistency. We use the power tensor method defined earlier in the literature to study the new CMBR data. The orientation of these three orthogonal vectors, as well as the power associated…

Spectro-Imaging of the Asymmetric Inner Molecular and Dust Shell Region of the Mira Variable W Hya with MIDI/VLTI

Quirrenbach, A.; Lopez, B.; Kerschbaum, F. +4 more

Not Available

Based on observations made with the Very Large Telescope Interferometer (VLTI) at the Paranal Observatory under program IDs 083.D-0294, 084.D-0334, and 085.D-0201.

On X-ray pulsations in β Cephei-type variables

Hamann, W. -R.; Hubrig, S.; Oskinova, L. M. +4 more

Context. β Cep-type variables are early B-type stars that are characterized by oscillations observable in their optical light curves. At least one β Cep-variable also shows periodic variability in X-rays.
Aims: Here we study the X-ray light curves in a sample of β Cep-variables to investigate how common X-ray pulsations are for this type of s…