VLBI 2MASS radioastronomy project

The project of observing 834 galaxies using very long baseline interferometry for determining their precise positions and producing their radio images. These galaxies were detected in the Two Micron All Sky Survey.

Scientific goals of the project

Nearly all galaxy bulges contain super-massive black holes (SMBHs), so galaxy assembly by hierarchical merging should produce wide pairs of slowly inspiraling SMBHs that either stall as tight binaries with ~1 pc separation or merge and are kicked away from the galaxy nucleus by anisotropic gravitational radiation. We propose a systematic VLBA search for off-nuclear SMBHs and for tight SMBH pairs in a sample of 923 nearby (D~200 Mpc) 2MASS galaxies containing radio sources stronger than 100 mJy to address three scientific problems:

  1. SMBH/galaxy co-evolution implied by the SMBH/bulge mass correlation,

  2. the "merger tree" theory of SMBH evolution, and

  3. the expected contribution of merging SMBH binaries to the gravitational-wave background.

The VLBA at X band provides both

People

Team members (in alphabetic order):

Observing plan

Our complete sample of nearby stellar bulges begins with all 2MASS galaxies (Jarrett et al. 2000), regardless of optical morphology (spiral, elliptical, irregular, etc.), brighter than K20fe = 12.25 at λ = 2.2 μm, the wavelength at which luminosity is a good tracer of total stellar mass (Madau et al. 1998). The typical distance to these bright galaxies is ~200 Mpc, and a few of the most luminous elliptical galaxies are up to ~500 Mpc distant. For our SMBH tracer, we will use flat-spectrum cores of 923 NVSS sources stronger than 100 mJy at 1.4 GHz (Condon, in prep.) identified with these 2MASS galaxies.

In order to achieve a 6 mJy detection limit on a single baseline, we will make 8 min long on-source scans at the 512 Mbps data recording rate, single polarization, 2-bit sampling, 128 MHz total bandwidth. We are going to observe 15 experiments at the VLBA of 24 hours duration. During each session we are going to schedule 55—60 target sources.

Observations will be scheduled in the absolute astrometry mode that we designed for the highly successful VLBI Calibrator Survey program (e.g., Kovalev et al. 2007; Petrov et al. 2008). Target sources will be observed in a sequence that minimizes slewing, in two scans with 6 hour separations. Every 1—1.5 hours a burst of four strong calibrator sources spanning a wide elevation range will be monitored in order to provide robust estimates of the path delay in the neutral atmosphere. Absolute positions of the target sources will be derived using the analysis methods of the VLBA Calibrator Survey.

Source lists

Preliminary results

To date, positions of 455 out of 922 target sources have been determined.

Catalogue of source coordinates of targeted sources: v2m.sou     Format description

Position uncertainties due to random noise vary in the range [0.1, 43] mas with the median value 0.5 mas. Systematic errors caused by mismodeled ionosphere contribution are deemed to contribute at a level of 1—5 mas. They will be evaluated later.

List of 467 sources from bc191a-r/bc196a-zs/bc201aa-ab which were not detected.

The list of 584 sources with positions within 60" from a 2MASS galaxy list, sorted in increasing the distance VLBI/2MASS between a VLBI and a 2MASS object is available here. 2MASS positions are taken from the point source catalog (Positions of super-coadd centroids). A list of the same 584 sources but with positions taken the 2MASS point source catalogue is available here.

The coarse estimates of median correlated flux densities of detected sources at three ranges of projected baseline lengths.

Project Status

Data

Experiment Correlator output (FITS-IDI)   Log-files     Key file     Flux file     Position sol.     Prelim. map  
bc191a 2010_07_15_bc191a_01.fits bc191a   logs bc191a   key bc191a   flux bc191a   sol bc191a   maps
bc191b 2010_07_22_bc191b_01.fits bc191b   logs bc191b   key bc191b   flux bc191b   sol bc191b   maps
bc191c 2010_08_03_bc191c_01.fits bc191c   logs bc191c   key bc191c   flux bc191c   sol bc191c   maps
bc191d 2010_08_10_bc191d_01.fits bc191d   logs bc191d   key bc191d   flux bc191d   sol bc191d   maps
bc191e 2010_08_11_bc191e_01.fits bc191e   logs bc191e   key bc191e   flux bc191e   sol bc191e   maps
bc191f 2010_08_11_bc191f_01.fits bc191f   logs bc191f   key bc191f   flux bc191f   sol bc191f   maps
bc191g 2010_08_20_bc191g_01.fits bc191g   logs bc191g   key bc191g   flux bc191g   sol bc191g   maps
bc191h 2010_08_21_bc191h_01.fits bc191h   logs bc191h   key bc191h   flux bc191h   sol bc191h   maps
bc191i 2010_08_29_bc191i_01.fits bc191i   logs bc191i   key bc191i   flux bc191i   sol bc191i   maps
bc191j 2010_09_07_bc191j_01.fits bc191j   logs bc191j   key bc191j   flux bc191j   sol bc191j   maps
bc191k 2010_09_11_bc191k_01.fits bc191k   logs bc191k   key bc191k   flux bc191k   sol bc191k   maps
bc191l 2010_09_14_bc191l_01.fits bc191l   logs bc191l   key bc191l   flux bc191l   sol bc191l   maps
bc191m 2010_09_16_bc191m_01.fits bc191m   logs bc191m   key bc191m   flux bc191m   sol bc191m   maps
bc191n 2010_10_23_bc191n_01.fits bc191n   logs bc191n   key bc191n   flux bc191n   sol bc191n   maps
bc191o 2010_12_11_bc191o_01.fits bc191o   logs bc191o   key bc191o   flux bc191o   sol bc191o   maps
bc191p 2010_12_12_bc191p_01.fits bc191p   logs bc191p   key bc191p   flux bc191p   sol bc191p   maps
bc191q 2010_12_19_bc191q_01.fits bc191q   logs bc191q   key bc191q   flux bc191q   sol bc191q   maps
bc191r 2010_12_21_bc191r_01.fits bc191r   logs bc191r   key bc191r   flux bc191r   sol bc191r   maps
bc196a 2011_01_13_bc196a_01.fits bc196a   logs bc196a   key bc196a   flux bc196a   sol bc196a   maps
bc196b 2011_01_15_bc196b_01.fits bc196b   logs bc196b   key bc196b   flux bc196b   sol bc196b   maps
bc196c 2011_01_20_bc196c_01.fits bc196c   logs bc196c   key bc196c   flux bc196c   sol bc196c   maps
bc196d 2011_01_21_bc196d_01.fits bc196d   logs bc196d   key bc196d   flux bc196d   sol bc196d   maps
bc196e 2011_02_01_bc196e_01.fits bc196e   logs bc196e   key bc196e   flux bc196e   sol bc196e   maps
bc196f 2011_02_07_bc196f_01.fits bc196f   logs bc196f   key bc196f   flux bc196f   sol bc196f   maps
bc196g 2011_02_16_bc196g_01.fits bc196g   logs bc196g   key bc196g   flux bc196g   sol bc196g   maps
bc196h 2011_02_19_bc196h_01.fits bc196h   logs bc196h   key bc196h   flux bc196h   sol bc196h   maps
bc196i 2011_02_27_bc196i_01.fits bc196i   logs bc196i   key bc196i   flux bc196i   sol bc196i   maps
bc196j 2011_03_12_bc196j_01.fits bc196j   logs bc196j   key bc196j   flux bc196j   sol bc196j   maps
bc196k 2011_03_14_bc196k_01.fits bc196k   logs bc196k   key bc196k   flux bc196k   sol bc196k   maps
bc196l 2011_03_24_bc196l_01.fits bc196l   logs bc196l   key bc196l   flux bc196l   sol bc196l   maps
bc196m 2011_04_19_bc196m_01.fits bc196m   logs bc196m   key bc196m   flux bc196m   sol bc196m   maps
bc196n 2011_04_26_bc196n_01.fits bc196n   logs bc196n   key bc196n   flux bc196n   sol bc196n   maps
bc196o 2011_05_13_bc196o_01.fits bc196o   logs bc196o   key bc196o   flux bc196o   sol bc196o   maps
bc196p 2011_05_15_bc196p_01.fits bc196p   logs bc196p   key bc196p   flux bc196p   sol bc196p   maps
bc196q 2011_05_16_bc196q_01.fits bc196q   logs bc196q   key bc196q   flux bc196q   sol bc196q   maps
bc196r 2011_05_30_bc196r_01.fits bc196r   logs bc196r   key bc196r   flux bc196r   sol bc196r   maps
bc196s 2011_06_03_bc196s_01.fits bc196s   logs bc196s   key bc196s   flux bc196s   sol bc196s   maps
bc196t 2011_06_07_bc196t_01.fits bc196t   logs bc196t   key bc196t   flux bc196t   sol bc196t   maps
bc196u 2011_06_14_bc196u_01.fits bc196u   logs bc196u   key bc196u   flux bc196t   sol bc196t   maps
bc196v 2011_06_19_bc196v_01.fits bc196v   logs bc196v   key bc196v   flux bc196v   sol bc196v   maps
bc196w 2011_06_22_bc196w_01.fits bc196w   logs bc196w   key bc196w   flux bc196w   sol bc196w   maps
bc196x 2011_07_24_bc196x_01.fits bc196x   logs bc196x   key bc196x   flux bc196x   sol bc196x   maps
bc196y 2011_07_27_bc196y_01.fits bc196y   logs bc196y   key bc196y   flux bc196y   sol bc196y   maps
bc196z 2011_08_02_bc196z_01.fits bc196z   logs bc196z   key bc196z   flux bc196z   sol bc196z   maps
bc196za 2011_08_06_bc196za_01.fits bc196za   logs bc196za   key bc196za   flux bc196za   sol bc196za   maps
bc196zb 2011_08_14_bc196zb_01.fits bc196zb   logs bc196zb   key bc196zb   flux bc196zb   sol bc196zb   maps
bc196zc 2011_08_17_bc196zc_01.fits bc196zc   logs bc196zc   key bc196zc   flux bc196zc   sol bc196zc   maps
bc196zd 2011_08_30_bc196zd_01.fits bc196zd   logs bc196zd   key bc196zd   flux bc196zd   sol bc196zd   maps
bc196ze 2011_09_01_bc196ze_01.fits bc196ze   logs bc196ze   key bc196ze   flux bc196ze   sol bc196ze   maps
bc196zf 2011_09_07_bc196zf_01.fits bc196zf   logs bc196zf   key bc196zf   flux bc196zf   sol bc196zf   maps
bc196zg 2011_09_10_bc196zg_01.fits bc196zg   logs bc196zg   key bc196zg   flux bc196zg   sol bc196zg   maps
bc196zh 2011_10_12_bc196zh_01.fits bc196zh   logs bc196zh   key bc196zh   flux bc196zh   sol bc196zh   maps
bc196zi 2011_10_15_bc196zi_01.fits bc196zi   logs bc196zi   key bc196zi   flux bc196zi   sol bc196zi   maps
bc196zj 2011_10_15_bc196zj_01.fits bc196zj   logs bc196zj   key bc196zj   flux bc196zj   sol bc196zj   maps
bc196zk 2011_12_01_bc196zk_01.fits bc196zk   logs bc196zk   key bc196zk   flux bc196zk   sol bc196zk   maps
bc196zl 2011_12_07_bc196zl_01.fits bc196zl   logs bc196zl   key bc196zl   flux bc196zl   sol bc196zl   maps
bc196zm 2011_12_11_bc196zm_01.fits bc196zm   logs bc196zm   key bc196zm   flux bc196zm   sol bc196zm   maps
bc196zn 2011_12_19_bc196zn_01.fits bc196zn   logs bc196zn   key bc196zn   flux bc196zn   sol bc196zn   maps
bc196zo 2012_01_08_bc196zo_01.fits bc196zo   logs bc196zo   key bc196zo   flux bc196zo   sol bc196zo   maps
bc196zp 2012_01_09_bc196zp_01.fits bc196zp   logs bc196zp   key bc196zp   flux bc196zp   sol bc196zp   maps
bc196zq 2012_01_12_bc196zq_01.fits bc196zq   logs bc196zq   key bc196zq   flux bc196zq   sol bc196zq   maps
bc196zr 2012_01_13_bc196zr_01.fits bc196zr   logs bc196zr   key bc196zr   flux bc196zr   sol bc196zr   maps
bc196zs 2012_01_23_bc196zs_01.fits bc196zs   logs bc196zs   key bc196zs   flux bc196zs   sol bc196zs   maps
bc201aa 2012_02_02_bc201aa_01.fits bc201aa   logs bc201aa   key bc201aa   flux bc201aa   sol bc201aa   maps
bc201ab 2012_02_03_bc201ab_01.fits bc201ab   logs bc201ab   key bc201ab   flux bc201ab   sol bc201ab   maps

This web page was prepared by Leonid Petrov ()
Last update: 2012.02.18_16:14:01