The Milky Way Nuclear Star Cluster beyond 1 pc

Transcription

1 The Milky Way Nuclear Star Cluster beyond 1 pc Anja Feldmeier, Nadine Neumayer, Anil Seth, Rainer Schödel, P. T. de Zeeuw, Nora Lützgendorf, C. J. Walcher, Shogo Nishiyama, Markus Kissler-Patig Oct. 1, 213 Anja Feldmeier

2 Nuclear Star Clusters (NSCs) Milky Way NGC 4395 Detected in 5% to 75% of all galaxies Half-light radius 2-5 pc Dynamical mass M sun Complex SF history Scaling relations with galaxy properties Some contain a MBH NGC 4244 Oct. 1, 213 Anja Feldmeier 2

3 Nuclear Star Clusters (NSCs) Oct. 1, 213 Anja Feldmeier 3

4 Kinematic data set ISAAC long slit spectrograph Central field: ~4 x fields of 2 x16 size Oct. 1, 213 Anja Feldmeier 4

5 Kinematic data set ISAAC long slit spectrograph Central field: ~4 x fields of 2 x16 size Oct. 1, 213 Anja Feldmeier 5

6 Kinematic data set ISAAC long slit spectrograph Central field: ~4 x fields of 2 x16 size ~ micron, spectral resolution 68 km/s Oct. 1, 213 Anja Feldmeier 6

7 Kinematic data set Full area 4 x 3.5 ~ 9.6 x 8.4 pc Binning to 2.22 x 2.22 Oct. 1, 213 Anja Feldmeier 7

8 Kinematic data set Full area 4 x 3.5 ~ 9.6 x 8.4 pc Binning to 2.22 x 2.22 Foreground stars removed: 2MASS point source catalog (Skrutskie et al. 26) & SIRIUS/IRSF catalog (Nishiyama et al. 26) Only Stars with 1.5<H-K<3.5 in cube (Schödel et al. 21) Oct. 1, 213 Anja Feldmeier 8

9 H 2 gas emission Gaussian fit to H 2 emission line at µm 1- Q(1) Velocity Flux km/s -93 km/s Velocity [km/s] lg (maximum flux) Oct. 1, 213 Anja Feldmeier 9

10 H 2 gas emission Gaussian fit to H 2 emission line at µm 1- Q(1) Velocity Velocity dispersion km/s -93 km/s -2 > 9 km/s Velocity [km/s] Velocity dispersion [km/s] Oct. 1, 213 Anja Feldmeier 1

11 H 2 gas emission Gaussian fit to H 2 emission line at µm 1- Q(1) 25 [µm] [µm] Flux 2 Flux pixel pixel Oct. 1, 213 Anja Feldmeier 11

12 Stellar CO absorption ppxf fit to absorption lines (Cappellari & Emsellem 24) High resolution spectra (Wallace & Hinkle 1996) convolved to lower resolution Oct. 1, 213 Anja Feldmeier 12

13 Stellar CO absorption Comparison to previous results (McGinn et al. 1989) 1 r (parsec) r (parsec) V (km/s) -5 σ (km/s) 1-1 ISAAC data ISAAC data, forground stars removed McGinn et al r () r () Oct. 1, 213 Anja Feldmeier 13 5

14 Stellar CO absorption Voronoi binning (Cappellari & Copin 23) effect of binning 15 Velocity Velocity dispersion Velocity [km/s] Velocity dispersion [km/s] S/N =2, resolution ~3.5 or.14 pc Equivalent to Galaxy at ~29 kpc distance observed with.1 resolution Oct. 1, 213 Anja Feldmeier 14

15 Stellar CO absorption Voronoi binning (Cappellari & Copin 23) effect of binning 15 Velocity Velocity dispersion Velocity [km/s] Velocity dispersion [km/s] S/N =4, resolution ~12 or.5 pc Equivalent to Galaxy at ~1 Mpc distance observed with.1 resolution Oct. 1, 213 Anja Feldmeier 15

16 Stellar CO absorption Voronoi binning (Cappellari & Copin 23) effect of binning 15 Velocity Velocity dispersion Velocity [km/s] Velocity dispersion [km/s] S/N =6, resolution ~2 or.8 pc Equivalent to Galaxy at ~1.6 Mpc distance observed with.1 resolution Oct. 1, 213 Anja Feldmeier 16

17 Stellar CO absorption effect of foreground stars 15 Velocity Velocity dispersion Velocity [km/s] Velocity dispersion [km/s] S/N =4, including foreground stars Oct. 1, 213 Anja Feldmeier 17

18 Stellar CO absorption effect of foreground stars 15 Velocity Velocity dispersion Velocity [km/s] Velocity dispersion [km/s] S/N =4, after foreground star correction Oct. 1, 213 Anja Feldmeier 18

19 Stellar CO absorption 1-dim profile Circular bins around Sgr A* V rms = SQRT(V 2 +σ 2 ) Oct. 1, 213 Anja Feldmeier 19

20 Stellar CO absorption 1-dim profile r (parsec) with foreground stars without foreground stars with IRS7 V RMS (km/s) r () Circular bins around Sgr A* V rms = SQRT(V 2 +σ 2 ) Oct. 1, 213 Anja Feldmeier 2

21 Photometry from Spitzer/IRAC survey 4.5µm image (Stolovy et al. 26) Dust and extinction corrected (Poster by Devaky Kunneriath) Oct. 1, 213 Anja Feldmeier 21

22 Photometry from Spitzer/IRAC survey Multi-Gaussian expansion fit (Cappellari 22) r (parsec) L O /parsec major axis r () Oct. 1, 213 Anja Feldmeier 22

23 Photometry from Spitzer/IRAC survey Multi-Gaussian expansion fit (Cappellari 22) r (parsec) L O /parsec major axis minor r () Oct. 1, 213 Anja Feldmeier 23

24 Photometry from Spitzer/IRAC survey Multi-Gaussian expansion fit (Cappellari 22) r (parsec) L O /parsec major axis minor axis upper error lower error r () Oct. 1, 213 Anja Feldmeier 24

25 Axisymmetric Jeans models Jeans Anisotropic MGE dynamical models (JAM, Cappellari 28) Inclination=9, constant anisotropy β constant M/L 2 r (parsec) V RMS (km/s) 15 1 Best fit with χ 2 = 21.84, β =.6 (radial), M/L 4.5µm = M sun /L 4.5µm,sun M BH = 2.e6 ±1.e6 M sun r () Oct. 1, 213 Anja Feldmeier 25

26 Conclusions First map of stellar velocities of the NSC Foreground star removal has no big influence on the results Result of black hole mass fit from Jeans model is largely consistent with black hole mass from direct measurements Black hole mass is too low à do we underestimate black hole masses in other Galaxies? Radially varying M/L can fit the required black hole mass à constrain the M/L with stellar population analysis using KMOS data Oct. 1, 213 Anja Feldmeier 26