Related papers: The Megamaser Cosmology Project: I. VLBI observati…
We have conducted VLBI observations of water maser and radio continuum emission in the nucleus of NGC 3079. The 22 GHz maser emission arises in compact clumps, distributed along an axis that is aligned with the major axis of the galactic…
Radio images of maser spots in the infrared source GL2789, connected with the young stellar object V645 Cyg, have been obtained as a result of the radio interferometric observations of H2O maser at 22 GHz and methanol maser at 6.7 GHz, with…
As part of the Measuring Black Holes in Below Milky Way-mass (M$^\star$) galaxies (MBHBM$^\star$) Project, we present a dynamical measurement of the supermassive black hole (SMBH) mass in the nearby lenticular galaxy NGC 3593, using cold…
High-resolution observations of the central few 100 pc of the galactic nuclear environments remain prohibitive for large statistical samples, which are crucial for tracing the links between central black hole formation, galaxy formation and…
The co-evolution of galaxies and supermassive black holes (SMBHs) underpins our understanding of galaxy evolution, but different methods to measure SMBH masses have only infrequently been cross-checked. We attempt to identify targets to…
Water masers are good tracers of high-mass star-forming regions. Water maser VLBI observations provide a good probe to study high-mass star formation and the galactic structure. We plan to make a blind survey toward the northern Galactic…
We used the Very Long Baseline Array (VLBA) and the European VLBI Network (EVN) to perform phase-referenced VLBI observations of the three most powerful maser transitions associated with the high-mass star-forming region G28.87+0.07: the…
We present the first measurement of the mass of a supermassive black hole (SMBH) in the nearby double-barred spiral galaxy NGC 3504 as part of the Measuring Black Holes Below the Milky Way ($M_{\star}$) mass galaxies (MBHBM$_{\star}$)…
At cosmological distances, gravitational lensing can provide a direct measurement of supermassive black hole (SMBH) masses irrespective of their luminosities. Here, we directly estimate the mass of a SMBH in the brightest cluster galaxy…
Supermassive black hole (SMBH) masses can be measured by resolving the dynamical influences of the SMBHs on spatially-resolved tracers of the central potentials. Modern long-baseline interferometers have enabled the use of molecular gas as…
We report the detection of a 22GHz water maser line in the nearest (D~3.8Mpc) radio galaxy Centaurus A using the Australia Telescope Compact Array (ATCA). The line is centered at a velocity of ~960kms-1, which is redshifted by about…
We report VLBI observations of methanol masers in the brightest 5(1)-6(0) A+ transition at 6.7 GHz in NGC 281W, 18151-1208 and 19388+2357. Using the fringe rate method absolute positions were obtained for all observed sources. A linear…
Water vapor maser emission in the 6_{16}-5_{23} transition towards the narrow-line Seyfert 1 (NLS1) galaxy NGC 4051 has been discovered during an ongoing single-dish extragalactic water maser survey. The Doppler-shifted maser components…
NGC 4258 is well known for its 22 GHz water maser features that appear to reside in a thin Keplerian disk orbiting at R_0=0.13 pc. The influence of gravitational redshift on the level of maser saturation and the line strength and width of…
Theoretical research on extragalactic masers (and hence this review) is almost entirely directed toward 22 GHz water masers in circumnuclear disks with the focus being the near ideal masing disk at the nucleus of the galaxy NGC4258. The…
Water masers around an AGB star, IRC+60169, were observed at four epochs using the Japanese VLBI networks. The distribution of the maser features is limited in a thick-shell region, which has inner and outer expansion velocities of 7 km/s…
We have detected and confirmed five water maser complexes in the Andromeda Galaxy (M31) using the Green Bank Telescope. These masers will provide the high brightness temperature point sources needed for proper motion studies of M31,…
Key and still largely missing parameters for measuring the mass content and distribution of the Local Group are the proper motion vectors of its member galaxies. The problem when trying to derive the gravitational potential of the Local…
We use new precision measurements of black hole masses from water megamaser disks to investigate scaling relations between macroscopic galaxy properties and supermassive black hole (BH) mass. The megamaser-derived BH masses span 10^6-10^8…
The Galactic Center contains large amounts of molecular and ionized gas as well as a plethora of energetic objects. Water masers are an extinction-insensitive probe for star formation and thus ideal for studies of star formation stages in…