Search Publications

Antitruncated stellar light profiles in the outer regions of STAGES spiral galaxies: bulge or disc related?

Wolf, Christian; Aragón-Salamanca, Alfonso; Hoyos, Carlos +2 more

We present a comparison of azimuthally averaged radial surface brightness µ(r) profiles and analytical bulge-disc decompositions (de Vaucouleurs, r^1/4 bulge plus exponential disc) for spiral galaxies using Hubble Space Telescope/Advanced Camera for Surveys V-band imaging from the Space Telescope A901/2 Galaxy Evolution Survey (STA…

Auto-consistent metallicity and star formation history of the nearest blue compact dwarf galaxy NGC 6789

Pérez-Montero, E.; García-Benito, R.

We present a detailed auto-consistent study of the nearest blue compact dwarf galaxy NGC 6789 by means of optical and ultraviolet (UV) archive photometry data and optical long-slit Intermediate dispersion Spectrograph and Imaging System-William Herschel Telescope (WHT) spectroscopy observations of the five brightest star-forming knots. The analysi…

Riding the wake of a merging galaxy cluster

Fabian, A. C.; McNamara, B. R.; Russell, H. R. +7 more

Using William Herschel Telescope (WHT) Optically Adaptive System for Imaging Spectroscopy (OASIS) integral field unit observations, we report the discovery of a thin plume of ionized gas extending from the brightest cluster galaxy (BCG) in Abell 2146 to the subcluster X-ray cool core which is offset from the BCG by ∼37 kpc. The plume is greater th…

Data and two-dimensional scaling relations for galaxies in Abell 1689: a hint of size evolution at z∼ 0.2

Davies, Roger L.; Dalla Bontà, E.; Houghton, R. C. W. +1 more

We present imaging and spectroscopy of Abell 1689 (z= 0.183) from the Gemini multi-object spectrograph (GMOS) on the Gemini North telescope and the Advanced Camera for Surveys (ACS) on the Hubble Space Telescope (HST). We measure integrated photometry from the GMOS g' and r' images (for 531 galaxies) and surface photometry from the HSTF625W image …

The cosmic history of hot gas cooling and radio active galactic nucleus activity in massive early-type galaxies

Lehmer, B. D.; Alexander, D. M.; Brandt, W. N. +5 more

We study the X-ray properties of 393 optically selected early-type galaxies (ETGs) over the redshift range of z≈ 0.0-1.2 in the Chandra Deep Fields (CDFs). To measure the average X-ray properties of the ETG population, we use X-ray stacking analyses with a subset of 158 passive ETGs (148 of which were individually undetected in X-ray). This ETG su…

The pulse profile and spin evolution of the accreting pulsar in Terzan 5, IGR J17480-2446, during its 2010 outburst

Stella, L.; Tramacere, A.; Ferrigno, C. +9 more

We analyse the spectral and pulse properties of the 11 Hz transient accreting pulsar, IGR J17480-2446, in the globular cluster Terzan 5, considering all the available Rossi X-Ray Timing Explorer, Swift and INTEGRAL observations performed during the outburst shown between 2010 October and November.

By measuring the pulse phase evolution we con…

A Spitzer Space Telescope survey of massive young stellar objects in the G333.2-0.4 giant molecular cloud

Lo, Nadia; Burton, Michael G.; Cunningham, Maria R. +3 more

The G333 giant molecular cloud contains a few star clusters and H II regions, plus a number of condensations currently forming stars. We have mapped 13 of these sources with the appearance of young stellar objects (YSOs) with the Spitzer Infrared Spectrograph in the Short-Low, Short-High and Long-High modules (5-36 µm). We use these spectra …

Evolution of massive galaxy structural properties and sizes via star formation in the GOODS NICMOS Survey

Conselice, Christopher J.; Hartley, William G.; Mortlock, Alice +2 more

We present a study of the resolved star-forming properties of a sample of distant massive (M > 10¹¹ M_⊙) galaxies in the GOODS NICMOS Survey (GNS), based on deep Hubble Space Telescope imaging from the GOODS North and South fields. We derive dust corrected ultraviolet star formation rates (SFRs) as a function of radius for …

An alternative origin for debris rings of planetesimals

Nayakshin, Sergei; Cha, Seung-Hoon

Core accretion (CA), the most widely accepted scenario for planet formation, postulates existence of ∼ km-sized solid bodies, called planetesimals, arranged in a razor-thin disc in the earliest phases of planet formation. These objects coagulate by collisions, eventually building planetary cores. In the tidal downsizing (TD) hypothesis, an alterna…

Investigating the reflection contribution to the X-ray emission of Ton S180

Fabian, A. C.; Nardini, E.; Walton, D. J.

There is now growing evidence that the soft X-ray excess is almost ubiquitous among unobscured active galaxies. In spite of the various interpretations that have been considered in the past few years, the nature of this foremost spectral feature is not firmly established yet. In this context, we review from a reflection perspective the three highe…