The survey of Planetary Nebulae in Andromeda (M31): I. Imaging the disk and halo with MegaCam@CFHT

Abstract

The Andromeda (M31) galaxy subtends nearly 100 sq. deg. on the sky, with severe contamination from the Milky Way halo stars whose surface density displays a steep gradient across the entire M31 field-of-view. Planetary Nebulae (PNe) are a population of stars firmly associated with M31, that are excellent tracers of light, chemistry and motion in galaxies. We present a 16 sq. deg. survey of the disk and inner halo of M31 with MegaCam@CFHT to identify PNe, characterize their luminosity-specific PN number and luminosity function (PNLF). PNe were identified based on their bright OIII 5007 $\unicode{x212B}$ emission and absence of a continuum. Subsamples of the faint PNe were independently confirmed by matching with resolved Hubble Space Telescope sources from the PHAT survey and spectroscopic follow-up observations with HectoSpec@MMT. The current survey reaches 2 mag fainter than the previous most-sensitive survey. We identify 4289 PNe, of which only 1099 were previously known. By comparing the PN number density with the surface brightness profile of M31 out to ~30 kpc along the minor-axis, we find that the stellar population in the inner halo has a 7 times larger luminosity-specific PN number value than that of the disk. It indicates that the stellar population at deprojected minor-axis radii larger than ~10 kpc is different from that in the M31 disk. We measure the PNLF and find a bright cut-off and a slope consistent with the previous determination by Ciardullo et al. (1989). Interestingly, it shows a significant rise at the faint end, present in all radial bins covered by the survey, much steeper than that observed for the Magellanic clouds and Milky Way bulge. M31 shows two major episodes of star formation and the rise in the faint end of the PNLF is possibly associated with the older stellar population. It may also be a result of varying opacity of the PNe.

19 pages, 35 figures, Accepted for publication in A&A

References in corpus (28)

• Infrared Emission from Interstellar Dust. IV. The Silicate-Graphite-PAH Model in the Post-Spitzer Era
• New constraints on the chemical evolution of the solar neighbourhood and Galactic disc(s). Improved astrophysical parameters for the Geneva-Copenhagen Survey
• Tracing Galaxy Formation with Stellar Halos II: Relating Substructure in Phase- and Abundance-Space to Accretion Histories
• The Panchromatic Hubble Andromeda Treasury X. Ultraviolet to Infrared Photometry of 117 Million Equidistant Stars
• Kinematic properties of early-type galaxy haloes using planetary nebulae
• A deep kinematic survey of planetary nebulae in the Andromeda Galaxy using the Planetary Nebula Spectrograph
• Planetary nebulae as tracers of galaxy stellar populations
• Stellar Absorption Line Analysis of Local Star-Forming Galaxies: The Relation Between Stellar Mass, Metallicity, Dust Attenuation and Star Formation Rate
• The Radical Consequences of Realistic Satellite Orbits for the Heating and Implied Merger Histories of Galactic Disks
• Dissecting simulated disc galaxies II: the age-velocity relation
• The outer halo globular cluster system of M31 - II. Kinematics
• The Nature and Origin of Substructure in the Outskirts of M31. I. Surveying the Stellar Content with HST/ACS
• A clear age-velocity dispersion correlation in Andromeda's stellar disk
• The Nature and Origin of Substructure in the Outskirts of M31 -- II. Detailed Star Formation Histories
• The evolution of planetary nebulae IV. On the physics of the luminosity function
• The evolution of planetary nebulae. V. The diffuse X-ray emission
• The evolution of planetary nebulae VII. Modelling planetary nebulae of distant stellar systems
• The Planetary Nebula Spectrograph survey of S0 galaxy kinematics. Data and Overview
• Toward better simulations of planetary nebulae luminosity functions
• First detection and characterization of symbiotic stars in M31
• A SITELLE view of M31's central region - I: Calibrations and radial velocity catalogue of nearly 800 emission-line point-like sources
• The kinematics of local thick discs do not support an accretion origin
• Emission line objects in NGC 6822. New Planetary Nebula candidates
• A catalog of planetary nebula candidates and HII regions in NGC 3109
• Revised Simulations of the Planetary Nebulae Luminosity Function
• Studying the local magnetic field and anisotropy of magnetic turbulence by synchrotron polarization derivative
• A two-mode planetary nebula luminosity function
• Panchromatic Hubble Andromeda Treasury IX: A Photometric Survey of Planetary Nebulae in M31

Cited by in corpus (11)

• Inside Out and Upside-Down: The Roles of Gas Cooling and Dynamical Heating in Shaping the Stellar Age-Velocity Relation
• DESI Observations of the Andromeda Galaxy: Revealing the Immigration History of our Nearest Neighbor
• Elemental Abundances in M31: Gradients in the Giant Stellar Stream
• The stellar halo in Local Group Hestia simulations I. The in-situ component and the effect of mergers
• The survey of planetary nebulae in Andromeda (M31). IV. Radial oxygen and argon abundance gradients of the thin and thicker disc
• Fornax 3D project: automated detection of planetary nebulae in the centres of early-type galaxies and first results
• The survey of planetary nebulae in Andromeda (M31) VI. Kinematics of M31 inner-halo substructures and comparison with major-merger simulation predictions
• Resolving the Disc-Halo Degeneracy II: NGC 6946
• Unravelling stellar populations in the Andromeda Galaxy
• Resolved SPLASH Chemodynamics in Andromeda's PHAT Stellar Halo and Disk: On the Nature of the Inner Halo Along the Major Axis
• Asymmetric Drift of Andromeda Analogs in the IllustrisTNG Simulation