The halo of M105 and its group environment as traced by planetary nebula populations: II. Using kinematics of single stars to unveil the presence of intragroup light around the Leo I galaxies NGC 3384 and M105

Abstract

M105 is an early-type galaxy in the nearby Leo I group, the closest galaxy group to contain all galaxy types and therefore an excellent environment to explore the low-mass end of intra-group light (IGL) assembly. We present a new extended kinematic survey of planetary nebulae (PNe) in M105 and the surrounding 30'x30' in the Leo I group with the Planetary Nebula Spectrograph. We use PNe as kinematic tracers of the diffuse stellar light in the halo and IGL and employ Gaussian mixture models to separate contributions from the companion galaxy NGC 3384 and associate PNe with halo and IGL components around M105. We present a catalogue of 314 PNe and firmly associate 93 with NGC 3384 and 169 with M105. The PNe in M105 are further associated with its halo and the surrounding exponential envelope. We construct smooth velocity and velocity dispersion fields and calculate projected rotation, velocity dispersion, and ${\lambda }_R$ profiles for each component. Halo PNe exhibit declining velocity dispersion and rotation profiles, while the velocity dispersion and rotation of the exponential envelope increase notably at large radii. We identify three regimes with distinct kinematics that are linked to distinct stellar population properties: (i) the rotating core (within $1R_{\mathrm{eff}}$) formed in situ and dominated by metal-rich ([M/H]~0) stars likely formed in situ, (ii) the halo from 1 to $7.5R_{\mathrm{eff}}$ consisting of intermediate-metallicity stars ([M/H]>-1), either formed in situ or brought in through major mergers, and (iii) the exponential envelope reaching beyond our farthest data point at 16 $R_{\mathrm{eff}}$, predominately composed of metal-poor ([M/H]<-1) stars. The high velocity dispersion and moderate rotation of the latter are consistent with that measured for dwarf satellite galaxies in the Leo I group, indicating that the exponential envelope traces the transition to the IGL.

Submitted to A&A, comments welcome. 20 pages, 14 figures, abstract abridged

References in corpus (20)

• The NumPy array: a structure for efficient numerical computation
• astroquery: An Astronomical Web-Querying Package in Python
• The SAURON project -- IX. A kinematic classification for early-type galaxies
• Updated Nearby Galaxy Catalog
• Galaxy Groups within 3500 km s${}^{-1}$
• 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
• The Formation and Evolution of Intracluster Light
• Planetary nebulae as tracers of galaxy stellar populations
• The PN.S Elliptical Galaxy Survey: the dark matter in NGC 4494
• Dearth of dark matter or massive dark halo? Mass-shape-anisotropy degeneracies revealed by NMAGIC dynamical models of the elliptical galaxy NGC 3379
• The Metallicity Distribution of Intracluster Stars in Virgo
• The Cluster Velocity Dispersion of the Abell 2199 cD Halo of NGC 6166
• The stellar halos of ETGs in the IllustrisTNG simulations: II. Accretion, merger history, and dark halo connection
• The Planetary Nebula Spectrograph survey of S0 galaxy kinematics. Data and Overview
• Evolution of central dark matter of early-type galaxies up to z ~ 0.8
• Mass of the dynamically hot inner stellar halo predicts the ancient accreted stellar mass
• Counter-dispersed slitless-spectroscopy technique: planetary nebula velocities in the halo of NGC 1399
• The halo of M105 and its group environment as traced by planetary nebula populations: I. Wide-field photometric survey of planetary nebulae in the Leo I group
• Discovery of an Ultra-Faint Dwarf Galaxy in the Intracluster Field of the Virgo Center : A fossil of the First Galaxies?

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