A5066098750- Galaxies: Formation, Evolution, Phenomena
- Astrophysics and Star Formation Studies
- Astronomy and Astrophysical Research
- Stellar, planetary, and galactic studies
- Astronomical Observations and Instrumentation
- Astrophysics and Cosmic Phenomena
- Spectroscopy and Laser Applications
- Astrophysical Phenomena and Observations
- Gamma-ray bursts and supernovae
- Radio Astronomy Observations and Technology
- Scientific Research and Discoveries
- Pulsars and Gravitational Waves Research
- Atmospheric Ozone and Climate
- Adaptive optics and wavefront sensing
- Cosmology and Gravitation Theories
- Geophysics and Gravity Measurements
- Astro and Planetary Science
- Impact of Light on Environment and Health
- Superconducting and THz Device Technology
- Dark Matter and Cosmic Phenomena
- Particle Detector Development and Performance
- Cold Atom Physics and Bose-Einstein Condensates
- Particle physics theoretical and experimental studies
- Calibration and Measurement Techniques
- Modeling, Simulation, and Optimization
Universidad de Granada
2015-2024
European Southern Observatory
2011
Vrije Universiteit Brussel
2011
Institut d'Astrophysique de Paris
2011
National Institute of Astrophysics, Optics and Electronics
2010
Instituto de Astrofísica de Andalucía
2002-2009
University of Cambridge
1996-2008
CEA Paris-Saclay
2002-2007
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2002-2007
Université Paris Cité
2007
We have compared the metallicity (represented by oxygen abundance), Xo, and dust-to-gas ratio, , in a sample of dwarf galaxies. For irregulars (dIrrs) we find good correlation between two quantities, with power-law index 0.52 ± 0.25. Blue compact (BCD) galaxies do not show such correlation; addition, both ratio tend to be higher than for dIrrs. then developed simple but physical analytical model above relation. Comparing results data, conclude that (i) low values -Xo relation is...
Eight optical and four radio observatories have been intensively monitoring the BL Lac object 0716+714 in last years: 4854 data points collected UBVRI bands since 1994, while light curves extend back to 1978. Many of these are presented here for first time. The long-term trend shown by seems vary with a characteristic time scale about 3.3 years, longer period 5.5-6 years characterize variations. In general, colour indices only weakly correlated brightness. flux behaviour at different...
We present the first Herschel spectroscopic detections of [OI]63 and [CII]158 micron fine-structure transitions, a single para-H2O line from 35 x 15 kpc^2 shocked intergalactic filament in Stephan's Quintet. The is believed to have been formed when high-speed intruder group collided with clumpy intergroup gas. Observations PACS spectrometer provide evidence for broad (> 1000 km s^-1) luminous [CII] profiles, as well fainter [OI]63micron emission. SPIRE FTS observations reveal water emission...
Recycled dwarf galaxies can form in the collisional debris of massive galaxies. Theoretical models predict that, contrary to classical galaxies, these recycled should be free nonbaryonic dark matter. By analyzing observed gas kinematics such with help a numerical model, we demonstrate that they do contain component amounting about twice visible Staying within standard cosmological framework, this result most likely indicates presence large amounts unseen, presumably cold, molecular gas. This...
Of the blazars detected by EGRET in GeV γ-rays, 3C 279 is not only best observed but also one of monitored at lower frequencies. We have assembled 11 spectra, from GHz radio through time intervals observations. Although some data appeared previous publications, most are new, including taken during high states early 1999 and 2000. All spectra show substantial γ-ray contribution to total luminosity object; a state, dominates over that all other frequencies factor more than 10. There no clear...
Aims: We characterize the molecular gas content using CO emission of a redshift-limited subsample isolated galaxies from AMIGA (Analysis interstellar Medium Isolated GAlaxies) project. Methods: present 12CO(1-0) data for 273 galaxies. constructed sample containing with 1500\kms
The radio continuum spectra of 14 star-forming galaxies are investigated by fitting nonthermal (synchrotron) and thermal (free-free) radiation laws. underlying measurements cover a frequency range ~325 MHz to 24.5 GHz (32 in case M82). It turns out that most these synchrotron not simple power-laws, but best represented low-frequency spectrum with mean slope alpha_nth = 0.59 +/- 0.20 (S_nu ~ nu^-alpha), break or an exponential decline the 1 - 12 GHz. Simple power-laws mildly curved lead...
The AMIGA project (Analysis of the Interstellar Medium Isolated Galaxies) is compiling a multiwavelength database isolated galaxies that includes optical (B and Hα), infrared (FIR NIR) radio (continuum plus HI CO lines) properties. It involves refinement pioneering Catalog Galaxies. This paper first in series begins with analysis global properties nearly redshift-complete CIG emphasis on Optical Luminosity Function (OLF) which we compare other recent estimates OLF for variety environments....
We investigate the process of galaxy formation as can be observed in only currently forming galaxies -the so-called Tidal Dwarf Galaxies, hereafter TDGs -through observations molecular gas detected via its CO (Carbon Monoxide) emission. These objects are formed material torn off outer parts a spiral disk due to tidal forces collision between two massive galaxies. Molecular is key element process, providing link cloud and bona fide galaxy. have 8 (two them already been published Braine et al....
Context.The AMIGA project aims to build a well defined and statistically significant reference sample of isolated galaxies in order estimate the environmental effects on formation evolution galaxies.
Tidal dwarf galaxies (TDGs) are recycled objects that form within the collisional debris of interacting/merging galaxies. They expected to be devoid non-baryonic dark matter, since they can only from dissipative material ejected discs progenitor We investigate gas dynamics in a sample six bona-fide TDGs around three interacting and post-interacting systems: NGC 4694, 5291, 7252 ("Atoms for Peace"). For 4694 5291 we analyse existing HI data Very Large Array (VLA), while present new...
We map for the first time two-dimensional H_2 excitation of warm intergalactic gas in Stephan's Quintet on group-wide (50 x 35 kpc^2) scales to quantify temperature, mass and warm-H_2 fraction as a function position using Spitzer. Molecular temperatures are seen rise (to T > 700K) slope power--law density-temperature relation flattens along main ridge filament, defining region maximum heating. also performed MHD modeling properties gas, velocity structure energy deposition rate slow fast...
How do galaxies transform from blue, star-forming spirals to red, quiescent early-type galaxies? To answer this question, we analyzed a set of 26 gas-rich, shocked post-starburst with Hubble Space Telescope (HST) imaging in B, I, and H bands, Sloan Digital Sky Survey (SDSS) i-band similar depth but lower resolution. We found that post-starbursts our sample have intermediate morphologies between disk- bulge-dominated (S\'ersic n$=1.7^{+0.3}_{-0.0}$) red bulges, likely due dust obscuration the...
We present new data of the dwarf galaxy NGC 1569 at 450 μm, 850 μm and 1200 taken with SCUBA JCMT bolometer array IRAM 30 m telescope. After including from IRAS 12, 25, 60 100 we have successfully fitted dust grain population model Désert et al. (1990) to observed midinfrared-to-millimetre spectrum. The fit requires a combination both large very small grains exposed strong radiation field as well an enhancement number relative grains. interpret this consequence destruction due shocks in...
view Abstract Citations (84) References (52) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Star Formation Activity in Spiral Galaxy Disks and the Properties of Radio Halos: Observational Evidence for a Direct Dependence Dahlem, Michael ; Lisenfeld, Ute Golla, Gotz In this article we address observationally question how SF disks galaxies leads to creation radio halos which minimum energy input into ISM is needed facilitate this. For investigation use sample...
We present high angular resolution ~1" and 0.6" mm-interferometric observations of the 12CO(1-0) 12CO(2-1) line emission in central 300pc late-type spiral galaxy NGC6946. The data, obtained with IRAM Plateau de Bure Interferometer (PdBI), allow first detection a molecular gas inner ~10" (270pc) large concentration (M(H_2) ~1.6x10^7M_sun) within 60pc. This nuclear clump shows evidence for ring-like geometry radius ~10pc as inferred from p-v diagrams. Both distribution well its kinematics can...
We present results from a Spitzer mid-infrared spectroscopy study of sample 74 galaxies located in 23 Hickson Compact Groups (HCGs), chosen to be at dynamically active stage H i depletion. find evidence for enhanced warm H2 emission (i.e., above that associated with UV excitation star-forming regions) 14 (∼20%), 8 having extreme values L(H2 S(0)-S(3))/L(7.7 μm polycyclic aromatic hydrocarbon), excess 0.07. Such has been seen previously the compact group HCG 92 (Stephan's Quintet), and was...
We present the discovery of a prominent bifurcation between early-type galaxies and late-type galaxies, in [4.6]–[12] μm colors from Wide Field Infrared Survey Explorer (WISE). then use an emission-line diagnostic comparison sample to explore nature objects found both within near edges this WISE infrared transition zone (IRTZ). hypothesize that might be due presence hot dust polyaromatic hydrocarbon (PAH) emission features galaxies. Using selected through Shocked Poststarburst Galaxy...
ABSTRACT We present new and archival atomic hydrogen (H i) observations of 15 the most massive spiral galaxies in local Universe (${M_{\star }}\gt 10^{11} \, {\rm M}_\odot$). From 3D kinematic modeling datacubes, we derive extended H i rotation curves, from these, estimate masses dark matter halos specific angular momenta discs. confirm that lie at upper ends Tully–Fisher relation (mass vs velocity, M ∝ V4) Fall (specific momentum mass, j M0.6), both stellar baryonic forms, with no...
We present new data taken at 850 μm with SCUBA the James Clerk Maxwell Telescope for a sample of 19 luminous infrared galaxies. Fourteen galaxies were detected. have used these data, together fluxes 25, 60 and 100 from IRAS, to model dust emission. find that emission most can be described by an optically thin, single temperature exponent extinction coefficient (k∝λ−β) β≃1.4–2. A lower β≃1 is required two galaxies, Arp 220 NGC 4418. discuss various possibilities this difference conclude...