Unveiling the Boxy Bulge and Bar of the Andromeda Spiral Galaxy

  title={Unveiling the Boxy Bulge and Bar of the Andromeda Spiral Galaxy},
  author={Rachael L. Beaton and Steven R. Majewski and Puragra Guhathakurta and Michael F. Skrutskie and Roc M. Cutri and John Good and Richard J. Patterson and E. Athanassoula and Martin Bureau},
  journal={The Astrophysical Journal Letters},
  pages={L91 - L94}
A new, 2.8 deg2 J, H, Ks near-infrared (NIR) survey from the 2MASS 6X program across the extent of the optical disk of the Andromeda (M31) galaxy provides a clear view of the M31 center almost completely unfettered by dust extinction and reveals a high-contrast bulge with very boxy isophotes dominating the NIR light to a semimajor axis of ~700'' (2.6 kpc). The inner bulge (≲50'') isophotes are relatively circular but show some twisting. Beyond this, (1) the M31 bulge ellipticity increases, (2… 

Figures from this paper

The star formation history in the M31 bulge
We present the study of stellar populations in the central 5.5' (~1.2 kpc) of the M31 bulge by using the optical color magnitude diagram derived from HST ACS WFC/HRC observations. In order to enhance
The extended disc and halo of the Andromeda galaxy observed with Spitzer-IRAC
We present the first results from an extended survey of the Andromeda galaxy (M31) using 41.1 h of observations by Spitzer-IRAC at 3.6 and 4.5 µm. This survey extends previous observations to the
An almost head-on collision as the origin of two off-centre rings in the Andromeda galaxy
Numerical simulations indicate that both rings result from a companion galaxy plunging through the centre of the disk of M31, the closest spiral galaxy to the Milky Way, and the most likely interloper is M32.
Evidence for non-axisymmetry in M31 from wide-field kinematics of stars and gas
As the nearest large spiral galaxy, M31 provides a unique opportunity to learn about the structure and evolutionary history of this galaxy type in great detail. Among the many observing programs
The Herschel Exploitation of Local Galaxy Andromeda (HELGA) - I. Global far-infrared and sub-mm morphology
We have obtained Herschel images at five wavelengths from 100 to 500 micron of a ~5.5x2.5 degree area centred on the local galaxy M31 (Andromeda), our nearest neighbour spiral galaxy, as part of the
Sculpting Andromeda – made-to-measure models for M31’s bar and composite bulge: dynamics, stellar and dark matter mass
The Andromeda galaxy (M31) contains a box/peanut bulge (BPB) entangled with a classical bulge (CB) requiring a triaxial modelling to determine the dynamics, stellar, and dark matter mass. We
We present wide-field near-infrared J and Ks images of the Andromeda Galaxy (M31) taken with WIRCam at the Canada–France–Hawaii Telescope as part of the Andromeda Optical and Infrared Disk Survey.
The combination of large size, high stellar density, high metallicity, and Sérsic surface brightness profile of the spheroidal component of the Andromeda galaxy (M31) within Rproj  ∼  20 kpc suggests
Dust in the eye of Andromeda
We present new Herschel-derived images of warm dust in the Andromeda galaxy, M31, with unprecedented spatial resolution (∼30 pc), column density accuracy, and constraints on the three-dimensional
A wide-field H I mosaic of Messier 31 - II. The disk warp, rotation, and the dark matter halo
Aims. We test cosmological models of structure formation using the rotation curve of the nearest spiral galaxy, M 31, determined using a recent deep, full-disk 21-cm imaging survey smoothed to 466 pc


Unravelling the mystery of the M31 bar
The inclination of M31 is too close to edge-on for a bar component to be easily recognized and is not sufficiently edge-on for a boxy/peanut bulge to protrude clearly out of the equatorial plane.
The photometric structure of the inner Galaxy
The light distribution in the inner few kiloparsecs of the Milky Way is recovered non­ parametrically from a dust-corrected near-infrared COBEIDIRBE surface brightness map of the inner Galaxy. The
Improving the triaxial bulge model of M31
A detailed hydrodynamical model of the gas flow in the triaxial gravitational potential of the bulge of the Andromeda galaxy (M31) has recently been proposed by Berman, and shown to provide excellent
Spiral arms, bar shape and bulge microlensing in the Milky Way
A new model for the luminosity distribution in the inner Milky Way is found, using a non-parametric penalized maximum-likelihood algorithm to deproject a dereddened COBE/ DIRBE L-band map of the
Infrared Imaging of M82: a Starburst in an Edge-On Barred Galaxy
New 1-30-micron images of the starburst galaxy M82 are presented. The appearance of M82 at 2 microns indicates that a bar about 1 kpc long is located at its center. This bar may dramatically
Hydrodynamic simulations of the triaxial bulge of M 31
The interstellar gas flow in the inner disk of M 31 is modelled using a new, two dimensional, grid based, hydrodynamics code. The potential of the stellar bulge is derived from its surface brightness
K-band observations of boxy bulges – I. Morphology and surface brightness profiles
Kn-band images, unsharp-masked images, as well as major-axis and vertically- summed surface brightness profiles are presented for 30 edge-on spiral galaxies, most with a boxy or peanut-shaped (B/PS)
On the nature of bulges in general and of box/peanut bulges in particular: input from N-body simulations
Objects designated as bulges in disc galaxies do not form a homogeneous class. I distinguish three types: the classical bulges, the properties of which are similar to those of ellipticals and which
Erratum - the Photometric Properties of Box / Peanut Galactic Bulges
Optical and near-IR photometry is presented for a sample of 14 edge-on galaxies displaying «box/peanut» bulge structure. The observed luminosity distributions are modelled using a 2D non-linear,
Discovery of a Boxy Peanut-shaped Bulge in the Near-Infrared
We report on the discovery of a boxy peanut-shaped bulge in the highly inclined barred Seyfert 2 galaxy NGC 7582. The peanut shape is clearly evident in near-infrared JHK images but is obscured by