Nearby early-type galaxies with ionized gas. The UV emission from GALEX observations

Abstract

We present GALEX far-ultraviolet (FUV, ${\lambda }_{eff}$=1538 Å) and near-ultraviolet (NUV, ${\lambda }_{eff}$=2316 Å) surface photometry of 40 early-type galaxies (ETGs) selected from a wider sample of 65 nearby ETGs showing emission lines in their optical spectra. We derive FUV and NUV surface brightness profiles, (FUV-NUV) colour profiles and D${}_{25}$ integrated magnitudes. We extend the photometric study to the optical {\it r} band from SDSS imaging for 14 of these ETGs. In general, the (FUV-NUV) radial colour profiles become redder with galactocentric distance in both rejuvenated ($\le 4$ Gyr) and old ETGs. Colour profiles of NGC 1533, NGC 2962, NGC 2974, NGC 3489, and IC 5063 show rings and/or arm-like structures, bluer than the body of the galaxy, suggesting the presence of recent star formation. Although seven of our ETGs show shell systems in their optical image, only NGC 7135 displays shells in the UV bands. We characterize the UV and optical surface brightness profiles, along the major axis, using a Sersic law. The Sersic law exponent, $n$, varies from 1 to 16 in the UV bands. S0 galaxies tend to have lower values of $n$ ($\le 5$). The Sersic law exponent $n=4$ seems to be a watershed: ETGs with $n>4$ tend to have [$\alpha$/Fe] greater than 0.15, implying a short star-formation time scale. We find a significant correlation between the FUV$-$NUV colour and central velocity dispersions $\sigma$, with the UV colours getting bluer at larger $\sigma$. This trend is likely driven by a combined effect of `downsizing' and of the mass-metallicity relation.

Accepted for publication in MNRAS, 33 pages, 7 figures

References in corpus (42)

• Theoretical Modeling of Starburst Galaxies
• The Galaxy Evolution Explorer: A Space Ultraviolet Survey Mission
• The Host Galaxies and Classification of Active Galactic Nuclei
• The epochs of early-type galaxy formation as a function of environment
• The Sixth Data Release of the Sloan Digital Sky Survey
• The SAURON project - IV. The mass-to-light ratio, the virial mass estimator and the fundamental plane of elliptical and lenticular galaxies
• The formation history of elliptical galaxies
• Structure and Formation of Elliptical and Spheroidal Galaxies
• The SAURON project - V. Integral-field emission-line kinematics of 48 elliptical and lenticular galaxies
• The GALEX Ultraviolet Atlas of Nearby Galaxies
• On the shape of the light profiles of early-type galaxies
• A Significant Population of Red, Near-IR Selected High Redshift Galaxies
• GALEX UV Color-Magnitude Relations and Evidence for Recent Star Formation in Early-type Galaxies
• On the Origin of [OII] Emission in Red Sequence and Post-starburst Galaxies
• Recent Star Formation in the Extreme Outer Disk of M83
• The Frequency of Tidal Features Associated with Nearby Luminous Elliptical Galaxies from a Statistically Complete Sample
• Keck Spectroscopy of distant GOODS Spheroidal Galaxies: Downsizing in a Hierarchical Universe
• The effect of environment on the UV colour-magnitude relation of early-type galaxies
• The life-time of galactic bars: central mass concentrations and gravity torques
• A population of hot, dusty ultra-luminous galaxies at z~2
• Nearby early-type galaxies with ionized gas. III. Analysis of line-strength indices with new stellar population models
• The Optical and Near-Infrared Morphologies of Isolated Early Type Galaxies
• On the Origin of the UV Upturn in Elliptical Galaxies. I. Sensitivity of UV Population Synthesis to Various Input Parameters
• Nearby early-type galaxies with ionized gas.IV. Origin and powering mechanism of the ionized gas
• Dynamical modelling of stars and gas in NGC2974: determination of mass-to-light ratio, inclination and orbital structure by Schwarzschild's method
• The star formation history of early-type galaxies as a function of mass and environment
• The Near-infrared S0 Survey III: Morphology of 15 Southern Early-type Disk Galaxies
• The SAURON project - XIII. SAURON-GALEX study of early-type galaxies: the ultraviolet colour-magnitude relations and Fundamental Planes
• GALEX UV Color Relations for Nearby Early-Type Galaxies
• The HI content of early-type galaxies from the ALFALFA survey. II. The case of low density environments
• Outlying HII Regions in HI-Selected Galaxies
• The GALEX UV emission in shell galaxies: tracing galaxy "rejuvenation" episodes
• UV Emission from Stellar Populations within Tidal Tails: Catching the Youngest Galaxies in Formation?
• Demography of SDSS early-type galaxies from the perspective of radial color gradients
• Star formation and figure rotation in the early-type galaxy NGC2974
• The mid-infrared colour-magnitude relation of early-type galaxies in the Coma cluster as measured by Spitzer-IRS
• Nearby early-type galaxies with ionized gas.I. Line-strength indices of the underlying stellar population
• Exploring the formation of spheroidal galaxies out to z~1.5 in GOODS
• Nearby early-type galaxies with ionized gas.II. Line-strength indices for 18 additional galaxies
• GALEX UV properties of the polar ring galaxy MCG-05-07-001 and the shell galaxies NGC 1210 and NGC 5329
• Decoding the spectra of SDSS early-type galaxies: New indicators of age and recent star formation
• Stellar Kinematics and Populations of Early-Type Galaxies with the SAURON and OASIS Integral-Field Spectrographs

Cited by in corpus (41)

• The Atlas3D project -- XXIX. The new look of early-type galaxies and surrounding fields disclosed by extremely deep optical images
• Confirmation of a Star Formation Bias in Type Ia Supernova Distances and its Effect on Measurement of the Hubble Constant
• Raining on black holes and massive galaxies: the top-down multiphase condensation model
• Molecular Gas in the X-ray Bright Group NGC 5044 as Revealed by ALMA
• Galaxy-scale Star Formation on the Red Sequence: the Continued Growth of S0s and the Quiescence of Ellipticals
• Dependence of the LMXB population on stellar age
• Nearby early-type galaxies with ionized gas VI. The Spitzer-IRS view
• Extended UV Disks and UV-Bright Disks in Low-Mass E/S0 Galaxies
• A Spitzer-IRS Spectroscopic atlas of early-type galaxies in the Revised Shapley-Ames Catalog
• Tracing rejuvenation events in nearby S0 galaxies
• Spiral-like star-forming patterns in CALIFA early-type galaxies
• Star-Formation Bimodality in Early-Type Galaxies
• The ($NUV-r$) vs. $M_r$ as a tracer of early-type galaxies evolution in USGC U376 and LGG 225 groups
• What drives the ultra-violet colours of passive galaxies?
• Catching Spiral - S0 transition in groups. Insights from SPH simulations with chemo-photometric implementation
• VEGAS: a VST Early-type GAlaxy Survey. IV. NGC 1533, IC 2038 and IC 2039: an interacting triplet in the Dorado group
• The spatial distribution and origin of the FUV excess in early-type galaxies
• Integral Field Spectroscopy of the inner kpc of the elliptical galaxy NGC 5044
• A Compact Jet at the Infrared Heart of the Prototypical Low-Luminosity AGN in NGC 1052
• Investigating early-type galaxy evolution with a multiwavelength approach. II. The UV structure of 11 galaxies with Swift-UVOT
• Nature vs. nurture in the low-density environment: structure and evolution of early-type dwarf galaxies in poor groups
• Signatures of recent star formation in ring S0 galaxies
• Morphology and surface photometry of a sample of isolated early-type galaxies from deep imaging
• Lenticular galaxies with UV-rings
• Tracing the evolution of nearby early-type galaxies in low density environments. The Ultraviolet view from GALEX
• Investigating early-type galaxy evolution with a multi-wavelength approach. III. Insights from SPH simulations with chemo-photometric implementation
• NGC 3934: a shell galaxy in a compact galaxy environment
• The NGC 454 system: anatomy of a mixed on-going merger
• Ionised gas abundances in barred spiral galaxies
• High-velocity feature as the indicator of the stellar population of Type Ia supernovae
• Old and New Major Mergers in the SOSIMPLE galaxy, NGC 7135
• Dorado and its member galaxies. Ha imaging of the group backbone
• Dorado and its member galaxies. III. Mapping star formation with FUV imaging from UVIT
• A multi-wavelength study of the evolution of Early-Type Galaxies in Groups: the ultraviolet view
• Galaxy evolution in groups. USGC U268 and USGC U376 in the Leo cloud
• Insights into the evolution of five isolated galaxies
• Spectral Energy Distribution Mapping of Two Elliptical Galaxies on sub-kpc scales
• A Spitzer-IRS view of early-type galaxies with cuspy/core nuclei and with fast/slow rotation
• Merging galaxies in isolated environments I. Multiband photometry, classification, stellar masses, and star formation rates
• Dorado and its member galaxies II. A UVIT picture of the NGC 1533 substructure
• Extraplanar emission in isolated edge-on late-type galaxies. I. The H$\alpha$ distribution versus to the old and young stellar discs