Search Publications
Dissection of the Collisional and Collisionless Mass Components in a Mini Sample of CLASH and HFF Massive Galaxy Clusters at z ≈ 0.4
Grillo, C.; Balestra, I.; Rosati, P. +7 more
We present a multiwavelength study of the massive ({M}200{{c}}≈ (1{--}2)× {10}15{M}⊙ ) galaxy clusters RXC J2248.7-4431, MACS J0416.1-2403, and MACS J1206.2-0847 at z ≈ 0.4. Using the X-ray surface brightness of the clusters from the deep Chandra data to model their hot gas, we are able to disentangle this mass ter…
On the Faint End of the Galaxy Luminosity Function in the Epoch of Reionization: Updated Constraints from the HST Frontier Fields
Castellano, M.; Di Criscienzo, M.; Santini, P. +12 more
Ultra-faint galaxies are hosted by small dark matter halos with shallow gravitational potential wells, hence their star formation activity is more sensitive to feedback effects. The shape of the faint end of the high-z galaxy luminosity function (LF) contains important information on star formation and its interaction with the reionization process…
The Carnegie-Irvine Galaxy Survey. VI. Quantifying Spiral Structure
Ho, Luis C.; Barth, Aaron J.; Yu, Si-Yue +1 more
The Carnegie-Irvine Galaxy Survey provides high-quality broadband optical images of a large sample of nearby galaxies for detailed study of their structure. To probe the physical nature and possible cosmological evolution of spiral arms, a common feature of many disk galaxies, it is important to quantify their main characteristics. We describe rob…
The Peculiar Radial Distribution of Multiple Populations in the Massive Globular Cluster M80
Dalessandro, E.; Salaris, M.; Vesperini, E. +7 more
We present a detailed analysis of the radial distribution of light-element multiple populations (LE-MPs) in the massive and dense globular cluster M80, based on a combination of UV and optical Hubble Space Telescope data. Surprisingly, we find that first-generation (FG) stars (FG) are significantly more centrally concentrated than extreme second-g…
Astrometric Limits on the Stochastic Gravitational Wave Background
Darling, Jeremy; Truebenbach, Alexandra E.; Paine, Jennie
The canonical methods for gravitational wave detection are ground- and space-based laser interferometry, pulsar timing, and polarization of the cosmic microwave background. But as has been suggested by numerous investigators, astrometry offers an additional path to gravitational wave detection. Gravitational waves deflect light rays of extragalact…
Rapid Buildup of a Magnetic Flux Rope during a Confined X2.2 Class Flare in NOAA AR 12673
Wang, Yuming; Liu, Lijuan; Cui, Jun +3 more
Magnetic flux ropes (MFRs) are believed to be the core structure in solar eruptions; nevertheless, their formation remains intensely debated. Here we report a rapid buildup process of an MFR system during a confined X2.2 class flare occurred on 2017 September 6 in NOAA active region (AR) 12673, three hours after which the structure erupted to a ma…
CLUMP-3D: Testing ΛCDM with Galaxy Cluster Shapes
Zitrin, Adi; Umetsu, Keiichi; Meneghetti, Massimo +5 more
The ΛCDM model of structure formation makes strong predictions on the concentration and shape of dark matter (DM) halos, which are determined by mass accretion processes. Comparison between predicted shapes and observations provides a geometric test of the ΛCDM model. Accurate and precise measurements needs a full three-dimensional (3D) analysis o…
The r-process Pattern of a Bright, Highly r-process-enhanced Metal-poor Halo Star at [Fe/H] ∼ -2
Beers, Timothy C.; Placco, Vinicius M.; Venn, Kim A. +9 more
A high-resolution spectroscopic analysis is presented for a new highly r-process-enhanced ([Eu/Fe] = 1.27, [Ba/Eu] = -0.65), very metal-poor ([Fe/H] = -2.09), retrograde halo star, RAVE J153830.9-180424, discovered as part of the R-Process Alliance survey. At V = 10.86, this is the brightest and most metal-rich r-II star known in the Milky Way hal…
Infrared Variability of Two Dusty White Dwarfs
Dufour, Patrick; Xu, Siyi; Gänsicke, Boris T. +11 more
The most heavily polluted white dwarfs often show excess infrared radiation from circumstellar dust disks, which are modeled as a result of tidal disruption of extrasolar minor planets. Interaction of dust, gas, and disintegrating objects can all contribute to the dynamical evolution of these dust disks. Here, we report two infrared variable dusty…
One Thousand Days of SN2015bn: HST Imaging Shows a Light Curve Flattening Consistent with Magnetar Predictions
Berger, Edo; Chornock, Ryan; Alexander, Kate D. +9 more
We present the first observations of a Type I superluminous supernova (SLSN) at ≳1000 days after maximum light. We observed SN 2015bn using the Hubble Space Telescope (HST) Advanced Camera for Surveys in the F475W, F625W and F775W filters at 721 days and 1068 days. SN 2015bn is clearly detected and resolved from its compact host, allowing reliable…