Spiral Galaxy Bulges, M31

We study the spin-up of primordial bulges due to the interaction with bars, using N-body simulations to follow the growth of the bar and the formation of a box/peanut bulge. We compare the resulting composite bulges with observations of nearby spiral galaxies.

Bhattacharya, S., Arnaboldi, M., Caldwell, N., Gerhard, O., Kobayashi, C., Hartke, J., Freeman, K. C., McConnachie, A. W., Guhathakurta, P., arXiv:2203.06428,
Radial oxygen and argon abundance gradients of the thin and thicker disc of Andromeda from planetary nebulae . 2022arXiv220306428

Bhattacharya, S., Arnaboldi, M., Gerhard, O., McConnachie, A., Caldwell, N., Hartke, J., Freeman, K. C., 2021, A&A, 647,A130,
The survey of planetary nebulae in Andromeda (M 31). III. Constraints from deep planetary nebula luminosity functions on the origin of the inner halo substructures in M 31. 2021A&A...647A.130B

Bhattacharya, S., Arnaboldi, M., Caldwell, N., Gerhard, O., Blaña Díaz, M., McConnachie, A., et al., 2019, A&A, 631, A56
The survey of planetary nebulae in Andromeda (M 31). II. Age-velocity dispersion relation in the disc from planetary nebulae. 2019A&A...631A..56B

Bhattacharya, S., Arnaboldi, M., Hartke, J., Gerhard, O., Comte, V., McConnachie, A., et al., 2019, A&A, 624, A132
The survey of planetary nebulae in Andromeda (M 31). I. Imaging the disc and halo with MegaCam at the CFHT. 2019A&A...624...A132

Blaña Díaz, M., Gerhard, O., Wegg, C., Portail, M., Opitsch, M., Saglia, R., et al., 2018, MNRAS, 481, 3210,
Sculpting Andromeda - made-to-measure models for M31's bar and composite bulge: dynamics, stellar and dark matter mass. 2018MNRAS.481.3210B

Blaña Díaz M., Wegg C., Gerhard O.,  Erwin P., Portail M., Opitsch M., Saglia R., Bender, R., 2017, MNRAS, 466, 4279
Andromeda chained to the Box - Dynamical Models for M31: Bulge & Bar eprint arXiv:1612.02319

Saha, K., Gerhard, O., Martinez-Valpuesta, I.,  2016, A&A, 588, A42
Spin-up of massive classical bulges during secular evolution.  2016MNRAS.463L..41B 

Saha, K., Gerhard, O.,  2013,  MNRAS,  430,  2039,   
Secular evolution and cylindrical rotation in boxy/peanut bulges: impact of initially rotating classical bulges. 2013MNRAS.430.2039S

Saha, K., Martinez-Valpuesta, I., Gerhard, O.,  2012,  MNRAS,  421,  333,   
Spin-up of low-mass classical bulges in barred galaxies. 2012MNRAS.421..333S