Discovery of an extended ultraviolet disk in the nearby galaxy NGC4625

Abstract

Recent far-UV (FUV) and near-UV (NUV) observations of the nearby galaxy NGC4625 made by the Galaxy Evolution Explorer (GALEX) show the presence of an extended UV disk reaching 4 times the optical radius of the galaxy. The UV-to-optical colors suggest that the bulk of the stars in the disk of NGC4625 are currently being formed, providing a unique opportunity to study today the physics of star formation under conditions similar to those when the normal disks of spiral galaxies like the Milky Way first formed. In the case of NGC4625, the star formation in the extended disk is likely to be triggered by interaction with NGC4618 and possibly also with the newly discovered galaxy NGC4625A. The positions of the FUV complexes in the extended disk coincide with peaks in the H I distribution. The masses of these complexes are in the range 10^3-10^4 Msun with their Halpha emission (when present) being dominated by ionization from single stars.

12 pages, 4 figures, accepted for publication in ApJL

References in corpus (18)

• Stellar population synthesis at the resolution of 2003
• The Galaxy Evolution Explorer: A Space Ultraviolet Survey Mission
• SINGS: The SIRTF Nearby Galaxies Survey
• Star Formation Thresholds in Galactic Disks
• Preparing Red-Green-Blue (RGB) Images from CCD Data
• The stellar populations of spiral galaxies
• Dust attenuation in the nearby Universe: comparison between galaxies selected in the ultraviolet or in the infrared
• The Westerbork HI Survey of Spiral and Irregular Galaxies I. HI Imaging of Late-type Dwarf Galaxies
• Recent Star Formation in the Extreme Outer Disk of M83
• Modelling the spectral energy distribution of galaxies. III. Attenuation of stellar light in spiral galaxies
• Ionizing Photon Emission Rates from O- and Early B-type Stars and Clusters
• Using Tidal Tails to Probe Dark Matter Halos
• The Westerbork HI Survey of Spiral and Irregular Galaxies II. R-Band Surface Photometry of Late-type Dwarf Galaxies
• {Chemo-spectrophotometric evolution of spiral galaxies: IV. Star formation efficiency and effective ages of spirals
• Recent star formation in nearby galaxies from GALEX imaging:M101 and M51
• A comparative study of the spatial distribution of ultraviolet and far-infrared fluxes from M 101
• The effects of dust in simple environments: Large Magellanic Cloud HII regions
• Neutral Hydrogen in the Interacting Magellanic Spirals NGC 4618/4625

Cited by in corpus (132)

• Star Formation in the Milky Way and Nearby Galaxies
• The GALEX Ultraviolet Atlas of Nearby Galaxies
• Galaxy And Mass Assembly (GAMA): end of survey report and data release 2
• The Spitzer Survey of Stellar Structure in Galaxies (S^4G)
• A characteristic oxygen abundance gradient in galaxy disks unveiled with CALIFA
• Extremely Inefficient Star Formation in the Outer Disks of Nearby Galaxies
• Beyond Inside-Out Growth: Formation and Evolution of Disk Outskirts
• A Search for Extended Ultraviolet Disk (XUV-disk) Galaxies in the Local Universe
• The structure of galactic disks: Studying late-type spiral galaxies using SDSS
• A GALEX Ultraviolet Imaging Survey of Galaxies in the Local Volume
• Legacy ExtraGalactic UV Survey (LEGUS) with The Hubble Space Telescope. I. Survey Description
• The Spatially Resolved Star Formation Law from Integral Field Spectroscopy: VIRUS-P Observations of NGC 5194
• The flat oxygen abundance gradient in the extended disk of M83
• Radial variation of attenuation and star formation in the largest late-type disks observed with GALEX
• Color Profiles of Spiral Galaxies: Clues on Outer-Disk Formation Scenarios
• Gas Metallicities in the Extended Disks of NGC 1512 and NGC 3621. Chemical Signatures of Metal Mixing or Enriched Gas Accretion?
• Radial distribution of stars, gas and dust in SINGS galaxies. I. Surface photometry and morphology
• The impact of bars on disk breaks as probed by S4G imaging
• Antitruncated Stellar Disks via Minor Mergers
• Radial Profiles of Star Formation in the Far Outer Regions of Galaxy Disks
• GALEX observations of Low Surface Brightness Galaxies: UV color and star formation efficiency
• Detection of PAH and Far-Infrared Emission from the Cosmic Eye: Probing the Dust and Star Formation of Lyman Break Galaxies
• The Baryonic Tully-Fisher Relationship for S${}^4$G Galaxies and the "Condensed" Baryon Fraction of Galaxies
• The spatially resolved star formation history of CALIFA galaxies: Cosmic time scales
• Tightly Correlated HI and FUV Emission in the Outskirts of M83
• Chemical and Photometric Evolution of Extended Ultraviolet Disks: Optical Spectroscopy of M83 (NGC5236) and NGC4625
• Morphology and environment of galaxies with disc breaks in the S4G and NIRS0S
• Gas Dynamics and Star Formation in the Galaxy Pair NGC1512/1510
• A Star Formation Law for Dwarf Irregular Galaxies
• The Galaxy Evolution Explorer (GALEX). Its legacy of UV surveys, and science highlights
• Cool dust heating and temperature mixing in nearby star-forming galaxies
• The Extended Optical Disk of M101
• On The Extended Knotted Disks of Galaxies
• Massive star formation in Wolf-Rayet galaxies. V: Star formation rates, masses and the importance of galaxy interactions
• Outlying HII Regions in HI-Selected Galaxies
• The Space Density of Extended Ultraviolet (XUV) Disks in the Local Universe and Implications for Gas Accretion on to Galaxies
• Searching for diffuse light in the M96 Group
• The Star Formation Threshold in NGC 6822
• GASP. XVI. Does cosmic web enhancement turn on star formation in galaxies?
• The Universal Initial Mass Function In The XUV Disk of M83
• The GALEX Ultraviolet Virgo Cluster Survey (GUViCS). II. Constraints on star formation in ram-pressure stripped gas
• The ACS Nearby Galaxy Survey Treasury II. Young Stars and their Relation to Halpha and UV Emission Timescales in the M81 Outer Disk
• Candidate Tidal Dwarf Galaxies in Arp 305: Lessons on Dwarf Detachment and Globular Cluster Formation
• Spitzer Observations of Star Formation in the Extreme Outer Disk of M83 (NGC5236)
• Cosmic Evolution of Stellar Disk Truncations: From z~1 to the Local Universe
• Collisional debris as laboratories to study star formation
• Stellar Populations and Radial Migrations in Virgo Disk Galaxies
• New Low Surface Brightness Dwarf Galaxies Detected Around Nearby Spirals
• The GALEX/S4G Surface Brightness and Color Profiles Catalog - I. Surface Photometry and Color Gradients of Galaxies
• On the Nature of Star Formation at Large Galactic Radii
• Extended UV Disks and UV-Bright Disks in Low-Mass E/S0 Galaxies
• The sub-galactic and nuclear main sequences for local star-forming galaxies
• The properties of the Malin 1 galaxy giant disk: A panchromatic view from the NGVS and GUViCS surveys
• Modelling the cosmic spectral energy distribution and extragalactic background light over all time
• PINGS: the PPAK IFS Nearby Galaxies Survey
• A Predicted Correlation Between Age Gradient and Star Formation History in FIRE Dwarf Galaxies
• Integral Field Spectroscopy and multi-wavelength imaging of the nearby spiral galaxy NGC5668: an unusual flattening in metallicity gradient
• Predicting the stellar and non-equilibrium dust emission spectra of high-resolution simulated galaxies with DART-Ray
• The Stellar Populations of M33's Outer Regions II: Deep ACS Imaging
• The Red and Featureless Outer Disks of Nearby Spiral Galaxies
• Star formation in the outskirts of DDO 154: A top-light IMF in a nearly dormant disc
• Simulations of XUV Disks with a Star Formation Density Threshold
• Spiral-Induced Star Formation in the Outer Disks of Galaxies
• On the Nature of the HII Regions in the Extended Ultraviolet Disc of NGC 4625
• Observational insights on the origin of giant low surface brightness galaxies
• An HI Threshold for Star Cluster Formation in Tidal Debris
• BlueMUSE: Project Overview and Science Cases
• Quantified H i Morphology VII: The Morphology of Extended Disks in UV and H i
• Impact of dark matter subhalos on extended HI disks of galaxies: Possible formation of HI fine structures and stars
• CO map and steep Kennicutt-Schmidt relation in the extended UV disk of M63
• Influence of galaxy stellar mass and observed wavelength on disc breaks in S${}^4$G, NIRS0S, and SDSS data
• Super-Chandrasekhar SNe Ia Strongly Prefer Metal-Poor Environments
• Unveiling the nature of M94's (NGC4736) outer region: a panchromatic perspective
• Radial Star Formation Histories in Fifteen Nearby Galaxies
• The Evolution of Stellar Populations in the Outer Disks of Spiral Galaxies
• A new reference catalogue for the very metal-poor Universe: +150 OB stars in Sextans A
• Star Formation and Gas Accretion in Nearby Galaxies
• Cosmic clocks: A Tight Radius - Velocity Relationship for HI-Selected Galaxies
• Comparing the Inner and Outer Star Forming Complexes in the Nearby Spiral Galaxies NGC 628, NGC 5457 and NGC 6946 using UVIT Observations
• Galaxy And Mass Assembly: the evolution of the cosmic spectral energy distribution from z = 1 to z = 0
• Stellar Populations in the Outer Disk and Halo of the Spiral Galaxy M101
• Star Formation on Galactic Scales: Empirical Laws
• The Impact of Stellar Migration on Disk Outskirts
• Metallicities in the Outer Regions of Spiral Galaxies
• First spectroscopic study of ionized gas emission lines in the extreme low surface brightness galaxy Malin 1
• Star-Forming Environments Throughout the M101 Group
• Star formation in the extended gaseous disk of the isolated galaxy CIG 96
• Globular Cluster Populations: First Results from S${}^4$G Early-Type Galaxies
• The radial distribution of supernovae compared to star formation tracers
• Star Cluster Populations in the Outer Disks of Nearby Galaxies
• Under Pressure: Star Clusters and the Neutral Hydrogen Medium of Tidal Tails
• A Mid-infrared Flare in the Active Galaxy MCG-02-04-026: Dust Echo of a Nuclear Transient Event
• The Surface Mass Density and Structure of the Outer Disk of NGC 628
• High Resolution H I Distributions and Multi-Wavelength Analyses of Magellanic Spirals NGC 4618 and NGC 4625
• First Detection of the Molecular Cloud Population in the Extended Ultraviolet (XUV) Disk of M83
• The Initial Mass Function in the Extended Ultraviolet Disk of M83
• ALMA CO(2-1) observations in the XUV disk of M83
• Cool Dust in the Outer Ring of NGC 1291
• The Larson-Tinsley Effect in the UV: Interacting vs. `Normal' Spiral Galaxies
• Tracing the outer disk of NGC 300: An ultraviolet view
• Outskirts of Nearby Disk Galaxies: Star Formation and Stellar Populations
• SDSS-IV MaNGA: Constraints on the Conditions for Star Formation in Galaxy Discs
• The H alpha Galaxy Survey VI. Star-forming companions of nearby field galaxies
• A Multi-Wavelength Study of Star Formation in 15 Local Star-Forming Galaxies
• Radial Distribution of Near-UV Flux in Disc Galaxies in the range 0<z<1
• Discovery of a Low-Redshift Damped Ly$\alpha$ System in a Foreground Extended Disk Using a Starburst Galaxy Background Illuminator
• Euclid: Early Release Observations -- The surface brightness and colour profiles of the far outskirts of galaxies in the Perseus cluster
• WALLABY Pilot Survey: Hydra Cluster Galaxies UV and HI morphometrics
• Spatially Correlated Cluster Populations in the Outer Disk of NGC 3184
• DIISC-II: Unveiling the Connections between Star Formation and ISM in the Extended Ultraviolet Disk of NGC 3344
• Studying the radio continuum from nuclear activity and star formation in Giant Low Surface Brightness Galaxies
• A pilot study using deep infrared imaging to constrain the star formation history of the XUV stellar populations in NGC 4625
• KMTNet Nearby Galaxy Survey III. Deficient H$\alpha$ flux in the Extended Disks of Spiral Galaxies
• Constraining the top-light initial mass function in the extended ultraviolet disk of M83
• A cosmologically motivated description of the dark matter halo profile for the Low Surface Brightness Galaxy, Malin 1
• Star formation in bulgeless late type galaxies: clues to their evolution
• New radial velocities for dwarf galaxies in the Local Volume
• Optical Detection of Star Formation in a Cold Dust Cloud in the Counterjet Direction of Centaurus A
• Gaseous nebulae and massive stars in the giant HI ring in Leo
• KMTNet Nearby Galaxy Survey: Overview and a Survey Description
• Study of Central Intensity Ratio of Seyfert Galaxies in nearby Universe
• The role of environment on the evolution of disc galaxies density profiles New insights from simulations and comparison to Euclid data
• Outer Disk Star Formation in HI selected Galaxies
• Characterizing the outer disk of eXtended-UV galaxies in the optical domain with deep surveys
• Rescuing the Initial Mass Function for Arp 78
• MUSE Study of Two Giant Low-surface-brightness Galaxies with Compact Satellites
• The 2X-HI disks of spiral galaxies
• An extended dust disk in a spiral galaxy; An occulting galaxy pair in ANGST
• Star Formation Beyond the Optical Disk : The Low-Density Outskirts of NGC2090
• The Color-Dependent Frequency of XUV Disks In Low-Mass E/S0s
• Size-Mass Relation Shows Its Colours: Contrasting Physical Imprints of Galaxy Evolution in Rest-Frame UV and Optical
• Compact and High Excitation Molecular Clumps in the Extended Ultraviolet Disk of M83