Evidence of extended [CII] and dust emission in local dwarf galaxies

Abstract

The evolution of dwarf galaxies is dramatically affected by gaseous and dusty outflows, which can easily deprive their interstellar medium of the material needed for the formation of new stars, simultaneously enriching their surrounding circumgalactic medium (CGM). In this letter, we present the first evidence of extended [CII] 158 $\mu$m line and dust continuum emission in local dwarf galaxies hosting star-formation-driven outflows. By stacking the [CII], far-infrared, and near-UV (NUV) emission obtained from Herschel and GALEX data, we derived the average radial profiles, and compared the spatial extension of gas, dust, and stellar activity in dwarf galaxies. We find that [CII] and dust emissions are comparable to each other, and more extended than the NUV continuum. The [CII] size is in agreement with that measured for $z>4$ star-forming galaxies, suggesting that similar mechanisms could be at the origin of the observed atomic carbon reservoir around local and high-$z$ sources. The cold dust follows the [CII] emission, going beyond the stellar continuum as opposed to what is typically observed in the early Universe where measurements can be affected by the poor sensitivity and faintness of dust emission in the CGM of high-$z$ galaxies. We attribute the extended [CII] and dust continuum emission to the presence of galactic outflows. As local dwarf galaxies are considered analogs of primordial sources, we expect that comparable feedback processes can be at the origin of the observed [CII] halos at $z>4$, dominating over other possible formation mechanisms.

8 pages, 4 figures, accepted for publication in A&A

References in corpus (18)

• The Circumgalactic Medium
• The Cosmic Baryon and Metal Cycles
• Very extended cold gas, star formation and outflows in the halo of a bright QSO at z>6
• The COS-Halos Survey: Origins of the Highly Ionized Circumgalactic Medium of Star-Forming Galaxies
• Observational constraints on the merger history of galaxies since $z\approx 6$: Probabilistic galaxy pair counts in the CANDELS fields
• The ALPINE-ALMA [CII] survey: Star-formation-driven outflows and circumgalactic enrichment in the early Universe
• Quasar-Mode Feedback in Nearby Type 1 Quasars: Ubiquitous Kiloparsec-Scale Outflows and Correlations with Black Hole Properties
• The Herschel Dwarf Galaxy Survey: II. Physical conditions, origin of [CII] emission, and porosity of the multiphase low-metallicity ISM
• The origin of dust in galaxies across cosmic time
• The ALPINE-ALMA [CII] survey: The contribution of major mergers to the galaxy mass assembly at z~5
• The gas, metal and dust evolution in low-metallicity local and high-redshift galaxies
• PetroFit: A Python Package for Computing Petrosian Radii and Fitting Galaxy Light Profiles
• An extended [CII] halo around a massive star-forming galaxy at z = 5.3
• IR SED and Dust Masses of Sub-solar Metallicity Galaxies at z~2.3
• Evidence for extended gaseous reservoirs around AGN at cosmic noon from ALMA CO(3-2) observations
• Constraining low redshift [CII] Emission by Cross-Correlating FIRAS and BOSS Data
• Exploring the Dust Content of Galactic Halos with Herschel. IV. NGC 3079
• The extended HI halo of NGC 4945 as seen by MeerKAT

Cited by in corpus (3)

• ColdSIM predictions of [C II] emission in primordial galaxies
• The ALPINE-ALMA [CII] Survey: Unveiling the baryon evolution in the ISM of $z\sim 5$ star-forming galaxies
• Nearby dwarf galaxies with extreme star formation rates: a window into dwarf-galaxy evolution in the early Universe