Search Publications
The Advanced Camera for Surveys Fornax Cluster Survey. VII. Half-light Radii of Globular Clusters in Early-type Galaxies
Jordán, Andrés; Infante, Leopoldo; Côté, Patrick +6 more
We measure the half-light radii of globular clusters (GCs) in 43 galaxies from the Advanced Camera for Surveys (ACS) Fornax Cluster Survey. We use these data to extend previous work in which the environmental dependencies of the half-light radii of GCs in early-type galaxies in the ACS Virgo Cluster Survey were studied, and a corrected mean half-l…
On the power spectrum of solar surface flows
Meunier, N.; Roudier, T.; Rieutord, M. +4 more
Context. The surface of the Sun provides us with a unique and very detailed view of turbulent stellar convection. Studying its dynamics can therefore help us make significant progress in stellar convection modelling. Many features of solar surface turbulence like the supergranulation are still poorly understood.
Aims: The aim of this work is …
The unusual N IV] -emitter galaxy GDS J033218.92-275302.7: star formation or AGN-driven winds from a massive galaxy at z = 5.56
Schaerer, D.; Dickinson, M.; Giavalisco, M. +8 more
Aims: We investigate the nature of the source GDS J033218.92-275302.7 at redshift ~5.56.
Methods: The spectral energy distribution of the source is well-sampled by 16 bands photometry from UV-optical (HST and VLT), near infrared, near infrared (VLT) to mid-infrared (Spitzer). The detection of a signal in the mid-infrared Spitzer/IRAC ban…
Herschel-ATLAS: Evolution of the 250 µm luminosity function out to z = 0.5
Rodighiero, G.; Valtchanov, I.; Ivison, R. J. +65 more
We have determined the luminosity function of 250 µm-selected galaxies detected in the ~14 deg2 science demonstration region of the Herschel-ATLAS project out to a redshift of z = 0.5. Our findings very clearly show that the luminosity function evolves steadily out to this redshift. By selecting a sub-group of sources within a fix…
On a New Near-Infrared Method to Estimate the Absolute Ages of Star Clusters: NGC 3201 as a First Test Case
Walker, A. R.; Prada Moroni, P. G.; Degl'Innocenti, S. +25 more
We present a new method to estimate the absolute ages of stellar systems. This method is based on the difference in magnitude between the main-sequence turnoff (MSTO) and a well-defined knee located along the lower main sequence (MSK). This feature is caused by the collisionally induced absorption of molecular hydrogen, and it can easily be identi…
A Herschel study of YSO evolutionary stages and formation timelines in two fields of the Hi-GAL survey
Smith, M. D.; Natoli, P.; Paladini, R. +28 more
We present a first study of the star-forming compact dust condensations revealed by Herschel in the two 2° × 2° Galactic Plane fields centered at [ℓ, b] = [30°, 0°] and [ℓ, b] =[59°, 0°] , respectively, and observed during the science demonstration phase for the Herschel Infrared GALactic plane survey (Hi-GAL) key-project. Compact source catalogs …
Revisiting the Parallax of the Isolated Neutron Star RX J185635-3754 Using HST/ACS Imaging
Neuhäuser, R.; Walter, F. M.; Lattimer, J. M. +3 more
We have redetermined the parallax and proper motion of the nearby isolated neutron star RX J185635-3754. We used eight observations with the high-resolution camera of the HST/ACS taken from 2002 through 2004. We performed the astrometric fitting using five independent methods, all of which yielded consistent results. The mean estimate of the paral…
Image Processing Techniques and Feature Recognition in Solar Physics
Aschwanden, Markus J.
This review presents a comprehensive and systematic overview of image-processing techniques that are used in automated feature-detection algorithms applied to solar data: i) image pre-processing procedures, ii) automated detection of spatial features, iii) automated detection and tracking of temporal features (events), and iv) post-processing task…
Towards a fully consistent Milky Way disc model - I. The local model based on kinematic and photometric data
Jahreiß, H.; Just, A.
We present a fully consistent evolutionary disc model of the solar cylinder. The model is based on a sequence of stellar subpopulations described by the star formation history (SFR) and the dynamical heating law [given by the age-velocity dispersion relation (AVR)]. The stellar subpopulations are in dynamical equilibrium and the gravitational pote…
Star Formation Efficiency in the Barred Spiral Galaxy NGC 4303
Momose, Rieko; Koda, Jin; Sawada, Tsuyoshi +1 more
We present new 12CO (J = 1 - 0) observations of the barred galaxy NGC 4303 using the Nobeyama 45 m telescope (NRO45) and the Combined Array for Research in Millimeter-wave Astronomy (CARMA). The Hα images of barred spiral galaxies often show active star formation in spiral arms, but less so in bars. We quantify the difference by measuri…