Discovery of faint double-peak Halpha emission in the halo of low redshift galaxies

Abstract

Aiming at the detection of cosmological gas being accreted onto galaxies of the local Universe, we examined the Halpha emission in the halo of 164 galaxies in the field of view of the Multi-Unit Spectroscopic Explorer Wide survey (\musew ) with observable Halpha (redshift < 0.42). An exhaustive screening of the corresponding Halpha images led us to select 118 reliable Halpha emitting gas clouds. The signals are faint, with a surface brightness of 10**(-17.3 pm 0.3) erg/s/cm2/arcsec2. Through statistical tests and other arguments, we ruled out that they are created by instrumental artifacts, telluric line residuals, or high redshift interlopers. Around 38% of the time, the Halpha line profile shows a double peak with the drop in intensity at the rest-frame of the central galaxy, and with a typical peak-to-peak separation of the order of pm 200 km/s. Most line emission clumps are spatially unresolved. The mass of emitting gas is estimated to be between one and 10**(-3) times the stellar mass of the central galaxy. The signals are not isotropically distributed; their azimuth tends to be aligned with the major axis of the corresponding galaxy. The distances to the central galaxies are not random either. The counts drop at a distance > 50 galaxy radii, which roughly corresponds to the virial radius of the central galaxy. We explore several physical scenarios to explain this Halpha emission, among which accretion disks around rogue intermediate mass black holes fit the observations best.

pay attention to the last sentence of the abstract! Accepted for publication in ApJ

References in corpus (39)

• Array Programming with NumPy
• Cold streams in early massive hot haloes as the main mode of galaxy formation
• Primordial Black Holes as Dark Matter: Recent Developments
• Cold gas accretion in galaxies
• The Chandra Deep Field-South Survey: 7 Ms Source Catalogs
• Streams, substructures and the early history of the Milky Way
• The MUSE Hubble Ultra Deep Field Survey: I. Survey description, data reduction and source detection
• The Cosmic Baryon and Metal Cycles
• Observational evidence for intermediate-mass black holes
• The Current Status of Galaxy Formation
• The MUSE 3D view of the Hubble Deep Field South
• Star formation sustained by gas accretion
• GHASP : An Halpha kinematic survey of spiral and irregular galaxies - VI. New Halpha data cubes for 108 galaxies
• The Second Data Release of the INT Photometric H-Alpha Survey of the Northern Galactic Plane (IPHAS DR2)
• The Lyman alpha Reference Sample: Extended Lyman alpha Halos Produced at Low Dust Content
• The Lyman-alpha Reference Sample: I. Survey outline and first results for Markarian 259
• The VLA Survey of the Chandra Deep Field South: I. Overview of the Radio Data
• MUSE searches for galaxies near very metal-poor gas clouds at z~3: new constraints for cold accretion models
• The X-SHOOTER Lyman-$\alpha$ survey at z=2 (XLS-z2) I: What makes a galaxy a Lyman-$\alpha$ emitter?
• The Tidal Disruption Event AT 2018hyz I: Double-peaked emission lines and a flat Balmer decrement
• The MUSE Extremely Deep Field: the Cosmic Web in Emission at High Redshift
• Multi-phase Circum-Galactic Medium probed with MUSE and ALMA
• Double-Peaked Balmer Emission Indicating Prompt Accretion Disk Formation in an X-Ray Faint Tidal Disruption Event
• Skycorr: A general tool for spectroscopic sky subtraction
• Metal-rich Damped/sub-Damped Lyman-alpha Quasar Absorbers at z<1
• Resolving shocks and filaments in galaxy formation simulations: effects on gas properties and star formation in the circumgalactic medium
• Star Clusters Around Recoiled Black Holes in the Milky Way Halo
• The evolution of the [OII], Hβ and [OIII] emission-line luminosity functions over the last nine billions years
• In search of cool flow accretion onto galaxies $-$ where does the disk gas end?
• MUSE Illuminates Channels for Lyman Continuum Escape in the Halo of SBS 0335-52E
• An anti-correlation between X-ray luminosity and H-alpha equivalent width in X-ray binaries
• Kinematics of Extremely Metal-poor Galaxies: Evidence for Stellar Feedback
• The content of astrophysical jets
• H-alpha Emission Variability in the gamma-ray Binary LS I +61 303
• High resolution H-alpha imaging of the Northern Galactic Plane, and the IGAPS images database
• SDSS-IV MaNGA: A serendipitous observation of a potential gas accretion event
• History of the gas fuelling star formation in eagle galaxies
• The Wyoming Survey for H-alpha. I. Initial Results at z ~ 0.16 and 0.24
• Optical and X-ray study of the peculiar high mass X-ray binary XMMU J010331.7-730144

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