Search Publications
Cluster richness-mass calibration with cosmic microwave background lensing
Geach, James E.; Peacock, John A.
Identifying galaxy clusters through overdensities of galaxies in photometric surveys is the oldest1,2 and arguably the most economical and mass-sensitive detection method3,4, compared with X-ray5-7 and Sunyaev-Zel'dovich effect8 surveys that detect the hot intracluster medium. However, a perennial proble…
Morphology Dependence of Stellar Age in Quenched Galaxies at Redshift ∼1.2: Massive Compact Galaxies Are Older than More Extended Ones
Giavalisco, Mauro; Bezanson, Rachel; Williams, Christina C. +6 more
We report the detection of morphology-dependent stellar age in massive quenched galaxies (QGs) at z ∼ 1.2. The sense of the dependence is that compact QGs are 0.5-2 Gyr older than normal-sized ones. The evidence comes from three different age indicators—{D}n4000, {{{H}}}δ , and fits to spectral synthesis models—applied to the…
Observations and Numerical Models of Solar Coronal Heating Associated with Spicules
De Pontieu, B.; McIntosh, S. W.; De Moortel, I. +1 more
Spicules have been proposed as significant contributors to the mass and energy balance of the corona. While previous observations have provided a glimpse of short-lived transient brightenings in the corona that are associated with spicules, these observations have been contested and are the subject of a vigorous debate both on the modeling and the…
Searching for Rapid Orbital Decay of WASP-18b
Wilkins, Ashlee N.; Deming, Drake; Delrez, Laetitia +4 more
The WASP-18 system, with its massive and extremely close-in planet, WASP-18b (M p = 10.3M J , a = 0.02 au, P = 22.6 hr), is one of the best-known exoplanet laboratories to directly measure Q‧, the modified tidal quality factor and proxy for efficiency of tidal dissipation, of the host star. Previous analysis predicted a ra…
Stellar Clusterings around "Isolated" Massive YSOs in the LMC
Ott, Jürgen; Hughes, Annie; Weisz, Daniel R. +10 more
Observations suggest that there is a significant fraction of O stars in the field of the Milky Way that appear to have formed in isolation or in low-mass clusters (<100 {M}⊙ ). The existence of these high-mass stars that apparently formed in the field challenges the generally accepted paradigm, which requires star formation to occur …
High Dense Gas Fraction in Intensely Star-forming Dusty Galaxies
Ivison, R. J.; Omont, A.; Bremer, M. +20 more
We present ALMA J=3{--}2 and VLA J=1{--}0 observations of the dense molecular gas tracers HCN, HCO+, and HNC in two lensed, high-redshift starbursts selected from the Herschel-ATLAS survey: H-ATLAS J090740.0-004200 (SDP.9, {z}{spec}=1.575) and H-ATLAS J091043.1-000321 (SDP.11, {z}{spec}=1.786). In SDP.9 we have det…
Martian magnetic storms
Luhmann, J. G.; Russell, C. T.; Li, Y. +11 more
The response of Mars to the major space weather events called interplanetary coronal mass ejections (ICMEs) is of interest for both general planetary solar wind interaction studies and related speculations on their evolutionary consequences—especially with respect to atmosphere escape. Various particle and field signatures of ICMEs have been obser…
Gas kinematics in powerful radio galaxies at z 2: Energy supply from star formation, AGN, and radio jets
Seymour, N.; De Breuck, C.; Nesvadba, N. P. H. +3 more
We compare the kinetic energy and momentum injection rates from intense star formation, bolometric AGN radiation, and radio jets with the kinetic energy and momentum observed in the warm ionized gas in 24 powerful radio galaxies at z ~ 2. These galaxies are among our best candidates for being massive galaxies near the end of their active formation…
HICOSMO: cosmology with a complete sample of galaxy clusters - II. Cosmological results
Reiprich, T. H.; Schellenberger, G.
The X-ray bright, hot gas in the potential well of a galaxy cluster enables systematic X-ray studies of samples of galaxy clusters to constrain cosmological parameters. HIFLUGCS consists of the 64 X-ray brightest galaxy clusters in the Universe, building up a local sample. Here, we utilize this sample to determine, for the first time, individual h…
Test of Parameterized Post-Newtonian Gravity with Galaxy-scale Strong Lensing Systems
Li, Xiaolei; Cai, Yongzhi; Cao, Shuo +3 more
Based on a mass-selected sample of galaxy-scale strong gravitational lenses from the SLACS, BELLS, LSD, and SL2S surveys and using a well-motivated fiducial set of lens-galaxy parameters, we tested the weak-field metric on kiloparsec scales and found a constraint on the post-Newtonian parameter γ ={0.995}-0.047+0.037 under th…