Insights into the evolution of five isolated galaxies

Abstract

The galaxy evolution is believed to be conditioned by the environment. Isolated galaxies or galaxies in poor groups are an excellent laboratory to study evolutionary mechanisms where effects of the environment are minimal. We present new {\it Swift}-{\tt UVOT} data in six filters, three in the ultraviolet (UV), of five isolated galaxies aiming at shedding light into their evolution. For all of our targets we present new UV integrated fluxes and for some of them also new UBV magnitudes. Our observations allow us to improve their multi-wavelength spectral energy distributions extending it over about 3 orders of magnitude in wavelength. We exploit our smooth-particle hydro-dynamical simulations with chemo-photometric implementation anchored, a posteriori, to the global multi-wavelength properties of our targets, to give insight into their evolution. Then we compare their evolutionary properties with those previously derived for several galaxies in groups. The evolution of our targets is driven by a merger occurred several Gyrs ago, in the redshift range $0.5\le z\le 4.5$, not unlike what we have already found for galaxies in groups. The merger shapes the potential well where the gas is accreting driving the star formation rate and the galaxy evolution. Isolated galaxies should not have suffered from interactions for at least 3\,Gyr. However, the initial merger is still leaving its signatures on the properties of our targets. Several rejuvenation episodes, triggered by {\it in situ} accretion, are highlighted. Moreover, jelly-fish morphologies appear as these galaxies achieve their maximum star formation rate, before their quenching phase.

25 pages, 19 figures, 10 tables, Accepted for pubblication in ApJ

References in corpus (25)

• Structural Properties of Pseudo-Bulges, Classical Bulges and Elliptical Galaxies: an SDSS Perspective
• A Classical Morphological Analysis of Galaxies in the Spitzer Survey of Stellar Structure in Galaxies (S4G)
• Paper II: Calibration of the Swift ultraviolet/optical telescope
• GHASP : An Halpha kinematic survey of spiral and irregular galaxies - VI. New Halpha data cubes for 108 galaxies
• Catalogues of isolated galaxies, isolated pairs, and isolated triplets in the local Universe
• The AMIGA sample of isolated galaxies. V. Quantification of the isolation
• Probing the merger history of red early-type galaxies with their faint stellar substructures
• The AMIGA sample of isolated galaxies III. IRAS data and infrared diagnostics
• The Galaxy End Sequence
• Formation of S0 galaxies through mergers. Bulge-disc structural coupling resulting from major mergers
• The AMIGA sample of isolated galaxies. IV. A catalogue of neighbours around isolated galaxies
• Barlenses and X-shape features compared: different manifestations of Boxy/Peanut bulges
• The New Galaxy Evolution Paradigm Revealed by the Herschel Surveys
• The AMIGA sample of isolated galaxies XIII. The HI content of an almost "nurture free" sample
• Update on HI data collection from GBT, Parkes and Arecibo telescopes for the Cosmic Flows project
• Are (pseudo)bulges in isolated galaxies actually primordial relics?
• A Comprehensive Examination of the Optical Morphologies of 719 Isolated Galaxies in the AMIGA Sample
• A star formation study of the ATLAS3D early-type galaxies with the AKARI all-sky survey
• A multiwavelength study of the Magellanic-type galaxy NGC 4449 - I. Modelling the spectral energy distribution, the ionization structure and the star formation history
• BVRI Surface Photometry of Isolated Spiral Galaxies
• Morphology and surface photometry of a sample of isolated early-type galaxies from deep imaging
• Revisiting the formation History of the minor-axis dust lane galaxy NGC1947
• The imprints of bars on the vertical stellar population gradients of galactic bulges
• The NGC 454 system: anatomy of a mixed on-going merger
• The UV window on counter rotating ETGs: insight from SPH simulations with chemo-photometric implementation