Search Publications
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…
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…
An X-Ray Periodicity of ∼1.8 hr in Narrow-line Seyfert 1 Galaxy Mrk 766
Zhang, Peng; Zhang, Peng-fei; Yan, Jing-zhi +2 more
In the narrow-line Seyfert 1 galaxy Mrk 766, a quasi-periodic oscillation (QPO) signal with a period of ∼6450 s is detected in the XMM-Newton data collected on 2005 May 31. This QPO signal is highly statistically significant at the ∼5σ confidence level, with a quality factor of Q=f/{{Δ }}f> 13.6. The X-ray intensity changed by a factor of 3, wi…
Mapping the Extinction Curve in 3D: Structure on Kiloparsec Scales
Peek, J. E. G.; Schlafly, E. F.; Finkbeiner, D. P. +1 more
Near-infrared spectroscopy from APOGEE and wide-field optical photometry from Pan-STARRS1 have recently made precise measurements of the shape of the extinction curve possible for tens of thousands of stars, parameterized by R(V). These measurements revealed structures in R(V) with large angular scales, which are challenging to explain in existing…
UVUDF: UV Luminosity Functions at the Cosmic High Noon
Gardner, Jonathan P.; Teplitz, Harry I.; Scarlata, Claudia +14 more
We present the rest-1500 Å UV luminosity functions (LF) for star-forming galaxies during the cosmic high noon—the peak of cosmic star formation rate at 1.5< z< 3. We use deep NUV imaging data obtained as part of the Hubble Ultra-Violet Ultra Deep Field (UVUDF) program, along with existing deep optical and NIR coverage on the HUDF. We select …
An Imperfectly Passive Nature: Bright Submillimeter Emission from Dust-obscured Star Formation in the z = 3.717 “Passive” System, ZF 20115
Ivison, R. J.; Smail, Ian; Dunlop, J. S. +28 more
The identification of high-redshift, massive galaxies with old stellar populations may pose challenges to some models of galaxy formation. However, to securely classify a galaxy as quiescent, it is necessary to exclude significant ongoing star formation, something that can be challenging to achieve at high redshifts. In this Letter, we analyze dee…