Search Publications

Quasar outflows and AGN feedback in the extreme UV: HST/COS observations of HE 0238-1904

Arav, Nahum; Borguet, Benoit; Chamberlain, Carter +2 more

Spectroscopic observations of quasar outflows at rest-frame 500-1000 Å have immense diagnostic power. We present analyses of such data, where absorption troughs from O IV and O IV* allow us to obtain the distance of the outflows from the AGN and troughs from Ne VIII and Mg X reveal the warm absorber phase of the outflow. Their inferred column dens…

HST hot-Jupiter transmission spectral survey: evidence for aerosols and lack of TiO in the atmosphere of WASP-12b

Aigrain, S.; Pont, F.; Fortney, J. J. +17 more

We present Hubble Space Telescope (HST) optical transmission spectra of the transiting hot-Jupiter WASP-12b, taken with the Space Telescope Imaging Spectrograph instrument. The resulting spectra cover the range 2900-10 300 Å which we combined with archival Wide Field Camera 3 spectra and Spitzer photometry to cover the full optical to infrared wav…

The UV and X-ray activity of the M dwarfs within 10 pc of the Sun

Liefke, C.; Micela, G.; Marino, A. +2 more

M dwarfs are the most numerous stars in the Galaxy. They are characterized by strong magnetic activity. The ensuing high-energy emission is crucial for the evolution of their planets and the eventual presence of life on them. We systematically study the X-ray and ultraviolet emission of a subsample of M dwarfs from a recent proper-motion survey, s…

The redshift and mass dependence on the formation of the Hubble sequence at z > 1 from CANDELS/UDS

Grogin, Norman A.; Kocevski, Dale D.; Koekemoer, Anton M. +16 more

In this paper we present a detailed study of the structures and morphologies of a sample of 1188 massive galaxies with M_* ≥ 10¹⁰ M_⊙ between redshifts z = 1 and 3 within the Ultra Deep Survey (UDS) region of the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS) field. Using this sample we dete…

The Herschel census of infrared SEDs through cosmic time

Berta, S.; Magnelli, B.; Nordon, R. +57 more

Using Herschel data from the deepest SPIRE and PACS surveys (HerMES and PEP) in COSMOS, GOODS-S and GOODS-N, we examine the dust properties of infrared (IR)-luminous (L_IR > 10¹⁰ L_⊙) galaxies at 0.1 < z < 2 and determine how these evolve with cosmic time. The unique angle of this work is the rigorous analys…

The sub-mJy radio sky in the Extended Chandra Deep Field-South: source population

Tozzi, P.; Mainieri, V.; Rosati, P. +5 more

The sub-mJy radio population is a mixture of active systems, that is star-forming galaxies (SFGs) and active galactic nuclei (AGNs). We study a sample of 883 radio sources detected at 1.4 GHz in a deep Very Large Array survey of the Extended Chandra Deep Field-South that reaches a best rms sensitivity of 6 µJy. We have used a simple scheme t…

Resolved debris discs around A stars in the Herschel DEBRIS survey

Matthews, Brenda C.; Duchêne, Gaspard; Kalas, Paul +12 more

The majority of debris discs discovered so far have only been detected through infrared excess emission above stellar photospheres. While disc properties can be inferred from unresolved photometry alone under various assumptions for the physical properties of dust grains, there is a degeneracy between disc radius and dust temperature that depends …

SN 2009ip à la PESSTO: no evidence for core collapse yet

Zhou, George; Fraser, Morgan; Benetti, Stefano +35 more

We present ultraviolet, optical and near-infrared observations of the interacting transient SN 2009ip, covering the period from the start of the outburst in 2012 October until the end of the 2012 observing season. The transient reached a peak magnitude of M_V = -17.7 mag, with a total integrated luminosity of 1.9 × 10⁴⁹ erg ov…

The evolution of the mass-size relation for early-type galaxies from z ∼ 1 to the present: dependence on environment, mass range and detailed morphology

Finoguenov, A.; Huertas-Company, M.; Kneib, J. P. +7 more

We study the dependence of the galaxy size evolution on morphology, stellar mass and large-scale environment for a sample of 298 group and 384 field quiescent early-type galaxies from the COSMOS survey, selected from z ∼ 1 to the present, and with masses log(M/M_⊙) > 10.5.

From a detailed morphological analysis we infer that ∼80 …

Interferometric radii of bright Kepler stars with the CHARA Array: θ Cygni and 16 Cygni A and B

Stello, D.; White, T. R.; Baron, F. +18 more

We present the results of long-baseline optical interferometry observations using the Precision Astronomical Visual Observations (PAVO) beam combiner at the Center for High Angular Resolution Astronomy (CHARA) Array to measure the angular sizes of three bright Kepler stars: θ Cygni, and both components of the binary system 16 Cygni. Supporting inf…