Search Publications
CLASH-VLT: Constraints on the Dark Matter Equation of State from Accurate Measurements of Galaxy Cluster Mass Profiles
Donahue, Megan; Broadhurst, Tom; Kuchner, Ulrike +39 more
A pressureless scenario for the dark matter (DM) fluid is a widely adopted hypothesis, despite the absence of direct observational evidence. According to general relativity, the total mass-energy content of a system shapes the gravitational potential well, but different test particles perceive this potential in different ways depending on their pr…
Coronal Inflows during the Interval 1996-2014
Sheeley, N. R., Jr.; Wang, Y. -M.
We extend our previous counts of coronal inflows from the 5 yr interval 1996-2001 to the 18 yr interval 1996-2014. By comparing stackplots of these counts with similar stackplots of the source-surface magnetic field and its longitudinal gradient, we find that the inflows occur in long-lived streams with counting rates in excess of 18 inflows per d…
The UV Continuum of z > 1 Star-forming Galaxies in the Hubble Ultraviolet UltraDeep Field
Finkelstein, Steven L.; Grogin, Norman A.; Koekemoer, Anton M. +11 more
We estimate the UV continuum slope, β, for 923 galaxies in the range 1 < z < 8 in the Hubble Ultradeep Field (HUDF). These data include 460 galaxies at 1 < z < 2 down to an absolute magnitude M_UV= -14(∼ 0.006 L^*z=1; 0.02 L^*z=0), comparable to dwarf galaxies in the local universe. We combine deep HST/UVIS photom…
Hubble Space Telescope Pre-perihelion ACS/WFC Imaging Polarimetry of Comet Ison (c/2012 s1) at 3.81 AU
Mutchler, Max; Muinonen, Karri; Hines, Dean C. +9 more
We present polarization images of Comet ISON (C/2012 S1) taken with the Hubble Space Telescope (HST) on UTC 2013 May 8 (r h = 3.81 AU, Δ = 4.34 AU), when the phase angle was α ≈ 12.°16. This phase angle is approximately centered in the negative polarization branch for cometary dust. The region beyond 1000 km (~0.32 arcsec ≈ 6 pixels) fr…
Strong Chromatic Microlensing in HE0047-1756 and SDSS1155+6346
Muñoz, J. A.; Mediavilla, E.; Rojas, K. +3 more
We use spectra of the double-lensed quasars HE0047-1756 and SDSS1155+6346 to study their unresolved structure through the impact of microlensing. There is no significant evidence of microlensing in the emission line profiles except for the Lyα line of SDSS1155+6346, which shows strong differences in the shapes for images A and B. However, the cont…
Neutral Interstellar Helium Parameters Based on Ulysses/GAS and IBEX-Lo Observations: What are the Reasons for the Differences?
Wood, B. E.; Katushkina, O. A.; Izmodenov, V. V. +1 more
Recent analysis of the interstellar helium fluxes measured in 2009-2010 at Earth's orbit by the Interstellar Boundary Explorer (IBEX) has suggested that the interstellar velocity (both direction and magnitude) is inconsistent with that derived previously from Ulysses/GAS observations made in the period from 1990 to 2002 at 1.5-5.5 AU from the Sun.…
Extreme Blazars Studied with Fermi-LAT and Suzaku: 1ES 0347-121 and Blazar Candidate HESS J1943+213
Cheung, C. C.; Fukazawa, Y.; Kataoka, J. +9 more
We report on our study of high-energy properties of two peculiar TeV emitters: the "extreme blazar" 1ES 0347-121 and the "extreme blazar candidate" HESS J1943+213 located near the Galactic plane. Both objects are characterized by quiescent synchrotron emission with flat spectra extending up to the hard X-ray range, and both were reported to be mis…
Interaction and Merging of two Sinistral Filaments
Liu, Yu; Wang, Haimin; Yang, Jiayan +4 more
In this paper, we report the interaction and subsequent merging of two sinistral filaments (F1 and F2) occurring at the boundary of AR 9720 on 2001 December 6. The two filaments were close and nearly perpendicular to each other. The interaction occurred after F1 was erupted and the eruption was impeded by a more extended filament channel (FC) stan…
The Inside-out Growth of the Most Massive Galaxies at 0.3 < z < 0.9
Gladders, M. D.; Yee, H. K. C.; Yan, Renbin +7 more
We study the surface brightness profiles of a sample of brightest cluster galaxies (BCGs) with 0.3 < z < 0.9. The BCGs are selected from the first Red-sequence Cluster Survey and an X-ray cluster survey. The surface brightness profiles of the BCGs are measured using HST ACS images, and the majority of them can be well modeled by a single Sér…
A Delayed Transition to the Hard State for 4U 1630-47 at the End of its 2010 Outburst
Kaaret, Philip; Yamaoka, Kazutaka; Kalemci, Emrah +3 more
Here we report on Swift and Suzaku observations near the end of an outburst from the black hole transient 4U 1630-47 and Chandra observations when the source was in quiescence. 4U 1630-47 made a transition from a soft state to the hard state ~50 days after the main outburst ended. During this unusual delay, the flux continued to drop, and one Swif…