The Supermassive Black Hole in NGC 4258 Distance, Mass and measuring the black hole bulge mass ratio Group 1: Rubén Herrero-Illana Joachim Janz Sara Lindgren Paulo Santos NGC 4258 (M106) 12:18:57.5 +47:18:14 7.44 Mpc H2O megamaser Observations VLBA 20m NOT Aim: Physical properties by using the water MASER Megamasers Megamasers Megamasers Megamasers Megamasers Megamasers Megamasers Very Long Baseline Array Observations at 22 GHz Bandwidth: 16 MHz Resolution: 31.25 KHz Redshifted + Systemic masers VLBA Data Reduction Calibration: AIPS + ParselTongue Imaging and deconvolution: CASA VLBA Data Cubes Click to edit Master text styles Second level ● Third level ● Fourth level ● Fifth level Redshifte d VLBA Data Cubes Click to edit Master text styles Second level ● Third level ● Fourth level ● Fifth level Systemic VLBA Results Click to edit Master text styles Second level ● Third level ● Fourth level ● Fifth level So far… so good So far… so good So far… so good 20-m single dish Gaussian fit 15.2 ± 0.1 km/s per year 5.2 ± 0.1 km/s per year Cross-correlation 5 km/s per year 1.6 1.4 1.2 1 ] y J [ y t 0.8 i s n e t n I 0.6 0.4 0.2 0 500 495 490 485 480 475 470 465 460 velocity [km/s] Result - VLBA and 20-m telescope Velocity: 956.6 ± 99.3 km/s Angular distance: -4.53 ± 2.18 milli-arcsec Distance to the NGC4258: 8.51 ± 5.93 Mpc Acceleration: 5.2 ± 0.1 km/s per year Radius of the inner region: 0.19 ± 0.09 pc Mass inside the inner radius: 3.98 ± 1.04 *107 M Nordic Optical Telescope B, R, J, H and K band M-to-L relation 12 Observation Sersic Exponential Model 13 2MASS 14 2 c 15 e s c r a / g a 16 m 17 18 19 0 20 40 60 80 100 arcsec compare with 2MASS compare sky frames and sky Disk – Exponential fit Bulge Sérsic fit– obtain the luminosity in in bulgethe the K-band Integral of profile to Integral of profile GALFIT software Calibrate with stars in the Bulge-disk decomposition Compare with M-to-L relation from previous literature: Bell and de Jong, ApJ, 2001 • Mass-to-light ratio of ~1.3 12.5 Marconi and Hunt 2003 12 Marconi and 11.5 11 K 10.5 M 10 9.5 9 8.5 -28 -27 -26 -25 -24 -23 -22 -21 -20 -19 log(BM) LK vs log(Mbulge) from literature: literature: vs log(Mbulge)LK from Hunt, ApJ, 2003 10 9.5 B-R M. and H. Marconi and Hunt 2003 9 8.5 ) H B M 8 ( g o l 7.5 7 6.5 6 8.5 9 9.5 10 10.5 11 11.5 12 12.5 log(bMulg)e 0.6*1010 M 0.6*1010 M 0.3*1010 Black hole to bulge mass relation Bulge mass Summary This project Literature Velocity 956.6 ± 99.3 km/s 1080 ± 2 km/s Angular distance -4.53 ± 2.18 milli- -4.4 milli-arcsec arcsec Acceleration 5.2 ± 0.1 km/s per 10 km/s per year year Radius of the inner 0.19 ± 0.09 pc 0.13 pc region Distance to NGC4258 8.51 ± 5.93 Mpc 7.44 Mpc Mass inside the inner 3.98 ± 1.04 *107 M 3.6*107 M radius Bulge mass 0.3-0.6 *1010 M 1.1 *1010 M.