Galactic Warp in the overdensity of the Canis Major Region

Abstract

Bellazzini et al. (2006b) claim that Lopez-Corredoira et al.'s (2002) warp model is totally unable to reproduce the Canis Major structure in the red clump stars. However, slight variations in the azimuth of the Lopez-Corredoira et al. (2002) warp model, justified by the uncertainties in the parameter as well as the local irregularities with respect to the average model, derive a result much closer to the observations of the overdensity south/north. The bump of red clump stars with m_K=13-13.5 around l=241 deg., b=-8.5 deg. and the depth of the Canis Major structure are also explainable in terms of the warp with an appropriate extrapolation of constant height between galactocentric radii of 13 and 16 kpc, as observed roughly in the southern warp, instead of a monotonically increasing height like the northern warp; and the observed velocity distribution of stars cannot exclude the warp possibility. A warp model is therefore still a possible explanation of the Canis Major overdensity, and the hypothesis of the existence of a dwarf galaxy is unnecessary, although still a possibility too.

arXiv comment6 pages, 3 figures, accepted to be published in MNRAS

References in corpus (12)

• Three Dimensional Structure of the Milky Way Disk
• COBE's Galactic Bar and Disk
• Old stellar Galactic disc in near-plane regions according to 2MASS: scales, cut-off, flare and warp
• Probing the Canis Major stellar over-density as due to the Galactic warp
• The Closest View of a Dwarf Galaxy: New Evidence on the Nature of the Canis Major over-density
• The age of the main population of the Sagittarius dwarf spheroidal galaxy. Solving the "M giant conundrum"
• The core of the Canis Major galaxy as traced by Red Clump stars
• Detection of a young stellar population in the background of open clusters in the Third Galactic Quadrant
• Why the Canis Major overdensity is not due to the Warp: analysis of its radial profile and velocities
• A radial velocity survey of low Galactic latitude structures: I. Kinematics of the Canis Major dwarf galaxy
• Absolute Proper Motion of the Canis Major Dwarf Galaxy Candidate
• Warps and correlations with intrinsic parameters of galaxies in the visible and radio

Cited by in corpus (15)

• Dark matter in the Milky Way, II. the HI gas distribution as a tracer of the gravitational potential
• The Milky Way's external disc constrained by 2MASS star counts
• The predicted luminous satellite populations around SMC and LMC-mass galaxies - A missing satellite problem around the LMC?
• A search for stellar tidal debris of defunct dwarf galaxies around globular clusters in the inner Galactic halo
• The AAT/WFI survey of the Monoceros Ring and Canis Major Dwarf galaxy: I. from l = (193 - 276)o
• No Excess of RR Lyrae Stars in the Canis Major Overdensity
• Vertical velocities from proper motions of red clump giants
• Reaffirming the connection between the Galactic stellar warp and the Canis Major overdensity
• Modeling Star counts in the Monoceros stream and the Galactic anti-centre
• A Canis Major over-density imaging survey. I. Stellar content and star-count maps : A distinctly elongated body of main sequence stars
• Spectroscopic hint of a cold stream in the direction of the globular cluster NGC 1851
• Saying Hallo to M94's Stellar Halo: Investigating the Accretion History of the Largest Pseudobulge Host in the Local Universe
• Astrophysics in 2006
• A revised view of the Canis Major stellar overdensity with DECam and Gaia: new evidence of a stellar warp of blue stars
• Solar Space Density of the Red Clump Stars and the Scale-length of the Thin Disc