Search Publications
Dynamical Measurements of Black Hole Masses in Four Brightest Cluster Galaxies at 100 Mpc
Ma, Chung-Pei; Graham, James R.; Gebhardt, Karl +5 more
We present stellar kinematics and orbit superposition models for the central regions of four brightest cluster galaxies, based upon integral-field spectroscopy at Gemini, Keck, and McDonald Observatories. Our integral-field data span radii from <100 pc to tens of kiloparsecs, comparable to the effective radius of each galaxy. We report black ho…
Panchromatic Observations of SN 2011dh Point to a Compact Progenitor Star
Sakamoto, T.; Zhang, X.; Cline, T. +32 more
We report the discovery and detailed monitoring of X-ray emission associated with the Type IIb SN 2011dh using data from the Swift and Chandra satellites, placing it among the best-studied X-ray supernovae (SNe) to date. We further present millimeter and radio data obtained with the Submillimeter Array, the Combined Array for Research in Millimete…
Constraints on cosmological models from strong gravitational lensing systems
Cao, Shuo; Biesiada, Marek; Zhu, Zong-Hong +2 more
Strong lensing has developed into an important astrophysical tool for probing both cosmology and galaxies (their structure, formation, and evolution). Using the gravitational lensing theory and cluster mass distribution model, we try to collect a relatively complete observational data concerning the Hubble constant independent ratio between two an…
The Star Formation History and Metal Content of the Green Peas. New Detailed GTC-OSIRIS Spectrophotometry of Three Galaxies
Amorín, R.; Pérez-Montero, E.; Vílchez, J. M. +1 more
We present deep broadband imaging and long-slit spectroscopy of three compact, low-mass starburst galaxies at redshift z ~ 0.2-0.3, also referred to as Green Peas (GP). We measure physical properties of the ionized gas and derive abundances for several species with high precision. We find that the three GPs display relatively low extinction, low o…
99 Herculis: host to a circumbinary polar-ring debris disc
Duchêne, G.; Wyatt, M. C.; Matthews, B. C. +6 more
We present resolved Herschel images of a circumbinary debris disc in the 99 Herculis system. The primary is a late F-type star. The binary orbit is well characterized and we conclude that the disc is misaligned with the binary plane. Two different models can explain the observed structure. The first model is a ring of polar orbits that move in a p…
The IRX-β relation on subgalactic scales in star-forming galaxies of the Herschel Reference Survey
Ciesla, L.; Buat, V.; Boquien, M. +13 more
Aims: It is still not understood why star-forming galaxies deviate from the ultraviolet colour-attenuation relation of starburst galaxies. Previous work and models hint that the role of the shape of the attenuation curve and the age of stellar populations play an important role. In this paper we aim at understanding the fundamental reasons fo…
Evolution of the Quasar Luminosity Function over 3 < z < 5 in the COSMOS Survey Field
Salvato, M.; Hasinger, G.; Capak, P. +10 more
We investigate the high-redshift quasar luminosity function (QLF) down to an apparent magnitude of I AB = 25 in the Cosmic Evolution Survey (COSMOS). Careful analysis of the extensive COSMOS photometry and imaging data allows us to identify and remove stellar and low-redshift contaminants, enabling a selection that is nearly complete fo…
The SLUGGS survey: calcium triplet-based spectroscopic metallicities for over 900 globular clusters
Spitler, Lee R.; Forbes, Duncan A.; Romanowsky, Aaron J. +6 more
Although the colour distribution of globular clusters in massive galaxies is well known to be bimodal, the spectroscopic metallicity distribution has been measured in only a few galaxies. After redefining the calcium triplet index-metallicity relation, we use our relation to derive the metallicity of 903 globular clusters in 11 early-type galaxies…
Analysis of astrometric catalogues with vector spherical harmonics
Mignard, F.; Klioner, S.
Aims: We compare stellar catalogues with position and proper motion components using a decomposition on a set of orthogonal vector spherical harmonics. We aim to show the theoretical and practical advantages of this technique as a result of invariance properties and the independence of the decomposition from a prior model.
Methods: We de…
Information Content of Exoplanetary Transit Spectra: An Initial Look
Line, Michael R.; Zhang, Xi; Yung, Yuk L. +3 more
It has been shown that spectroscopy of transiting extrasolar planets can potentially provide a wealth of information about their atmospheres. Herein, we set up the inverse problem in spectroscopic retrieval. We use nonlinear optimal estimation to retrieve the atmospheric state (pioneered for Earth sounding by Rodgers). The formulation quantifies t…