Search Publications
A New Relativistic Component of the Accretion Disk Wind in PDS 456
Reeves, J. N.; Braito, V.; Nardini, E. +3 more
Past X-ray observations of the nearby luminous quasar PDS 456 (at z = 0.184) have revealed a wide angle accretion disk wind, with an outflow velocity of ∼-0.25c. Here, we unveil a new, relativistic component of the wind through hard X-ray observations with NuSTAR and XMM-Newton, obtained in 2017 March when the quasar was in a low-flux state. This …
A Long Decay of X-Ray Flux and Spectral Evolution in the Supersoft Active Galactic Nucleus GSN 069
Shu, X. W.; Wang, J. X.; Wang, T. G. +3 more
GSN 069 is an optically identified very low-mass active galactic nuclei (AGN) that shows supersoft X-ray emission. The source is known to exhibit a huge X-ray outburst, with flux increased by more than a factor of ∼240 compared to the quiescence state. We report its long-term evolution in the X-ray flux and spectral variations over a timescale of …
Quantifying Feedback from Narrow Line Region Outflows in Nearby Active Galaxies. II. Spatially Resolved Mass Outflow Rates for the QSO2 Markarian 34
Kraemer, S. B.; Crenshaw, D. M.; Gandhi, P. +10 more
We present spatially resolved mass outflow rate measurements ({\dot{M}}out}) for the narrow line region of Markarian 34, the nearest Compton-thick type 2 quasar (QSO2). Spectra obtained with the Hubble Space Telescope and at Apache Point Observatory reveal complex kinematics, with distinct signatures of outflow and rotation within 2 kpc…
Price of shifting the Hubble constant
Evslin, Jarah; Ruchika; Sen, Anjan A.
An anisotropic measurement of the baryon acoustic oscillation (BAO) feature fixes the product of the Hubble constant and the acoustic scale H0rd. Therefore, regardless of the dark energy dynamics, to accommodate a higher value of H0 one needs a lower rd and so necessarily a modification of early time cos…
Molecular Gas Contents and Scaling Relations for Massive, Passive Galaxies at Intermediate Redshifts from the LEGA-C Survey
Muzzin, Adam; van Dokkum, Pieter; van der Wel, Arjen +13 more
A decade of study has established that the molecular gas properties of star-forming galaxies follow coherent scaling relations out to z ∼ 3, suggesting remarkable regularity of the interplay between molecular gas, star formation, and stellar growth. Passive galaxies, however, are expected to be gas-poor and therefore faint, and thus little is know…
Where does galactic dust come from?
Hunt, L. K.; Valiante, R.; Ginolfi, M. +5 more
Here we investigate the origin of the dust mass (Mdust) observed in the Milky Way (MW) and of dust scaling relations found in a sample of local galaxies from the DGS and KINGFISH surveys. To this aim, we model dust production from Asymptotic Giant Branch (AGB) stars and supernovae (SNe) in simulated galaxies forming along the assembly o…
Model independent inference of the expansion history and implications for the growth of structure
Joudaki, Shahab; Kirkby, David; Kaplinghat, Manoj +1 more
We model the expansion history of the Universe as a Gaussian process and find constraints on the dark energy density and its low-redshift evolution using distances inferred from the Luminous Red Galaxy and Lyman-alpha data sets of the Baryon Oscillation Spectroscopic Survey, supernova data from the Joint Light-Curve Analysis sample, cosmic microwa…
Optical-NIR dust extinction towards Galactic O stars
Maíz Apellániz, J.; Barbá, R. H.
Context. O stars are excellent tracers of the intervening ISM because of their high luminosity, blue intrinsic SED, and relatively featureless spectra. We are currently conducting the Galactic O-Star Spectroscopic Survey (GOSSS), which is generating a large sample of O stars with accurate spectral types within several kpc of the Sun.
Aims: We…
Dual Phase-space Cascades in 3D Hybrid-Vlasov-Maxwell Turbulence
Califano, F.; Cerri, S. S.; Kunz, M. W.
To explain energy dissipation via turbulence in collisionless, magnetized plasmas, the existence of a dual real- and velocity-space cascade of ion-entropy fluctuations below the ion gyroradius has been proposed. Such a dual cascade, predicted by the gyrokinetic theory, has previously been observed in gyrokinetic simulations of two-dimensional, ele…
Unveiling the Dynamical State of Massive Clusters through the ICL Fraction
Koekemoer, Anton M.; Donahue, Megan; Frye, Brenda L. +34 more
We have selected a sample of 11 massive clusters of galaxies observed by the Hubble Space Telescope in order to study the impact of the dynamical state on the intracluster light (ICL) fraction, the ratio of total integrated ICL to the total galaxy member light. With the exception of the Bullet cluster, the sample is drawn from the Cluster Lensing …