Open AccessA SAURON study of M32: measuring the intrinsic flattening and the central black hole mass
Author(s) -
Verolme E. K.,
Cappellari M.,
Copin Y.,
Van Der Marel R. P.,
Bacon R.,
Bureau M.,
Davies R. L.,
Miller B. M.,
De Zeeuw P. T.
Publication year - 2002
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.2002.05664.x
Subject(s) - flattening , physics , astrophysics , elliptical galaxy , spectrograph , william herschel telescope , galaxy , telescope , black hole (networking) , astronomy , spectral line , computer network , routing protocol , routing (electronic design automation) , computer science , link state routing protocol
We present dynamical models of the nearby compact elliptical galaxy M32, using high‐quality kinematic measurements, obtained with the integral‐field spectrograph SAURON mounted on the William Herschel Telescope on La Palma. We also include STIS data obtained previously by Joseph et al. We find a best‐fitting black hole mass of M • = (2.5 ± 0.5) × 10 6 M ⊙ and a stellar I ‐band mass‐to‐light ratio of (1.85 ± 0.15) M ⊙ /L ⊙ . For the first time, we are also able to constrain the inclination along which M32 is observed to 70°± 5° . Assuming that M32 is indeed axisymmetric, the averaged observed flattening of 0.73 then corresponds to an intrinsic flattening of 0.68 ± 0.03 . These tight constraints are mainly caused by the use of integral‐field data. We show this quantitatively by comparing with models that are constrained by multiple slits only. We show the phase‐space distribution and intrinsic velocity structure of the best‐fitting model and investigate the effect of regularization on the orbit distribution.