Scientists have precisely measured the mass of the central supermassive black hole in galaxy NGC 1097, and found it is 140 times more massive than the Sun.
Galaxies are believed to have evolved alongside their central supermassive black holes, and these findings could help shed light on the mysterious process, the National Institutes of Natural Sciences reported. The researchers made their findings using observational data taken by ALMA over only a two hour period.
Recent findings have suggested a correlation between central supermassive black hole (SMBH) mass and the central bulge of the host galaxy, indicating SMBHs may play a key role in the growth of galaxies. Measuring the exact mass of these black holes could help scientists understand this link.
To make these measurements the researchers strayed from conventional methods, and instead looked at molecular gas dynamics in the central region of the galaxy. Since ionized gas dynamic (which are used in common measurement methods) are easily disturbed by non-circular motion such as the inflow of gas, the researchers looked at molecular gas, which is not as easily influenced. This allowed the team to get a more accurate reading of the motion affected by SMBH gravity.
The team made precise measurements of the distribution and kinematics of molecular gas by looking at emission lines from hydrogen cyanide (HCN) and formyl cation (HCO+) with ALMA, and also took into account the gravitational motion of the molecular gas. The final calculations suggests the central SMBH of NGC1097 has a mass 140 million times the solar mass, marking the first-ever mass measurement using this method on late-type galaxies.
"We could obtain the kinematics data of the central molecular gas in NGC 1097 within a two-hour ALMA observation. To reveal the relation between the SMBH and the host galaxy, we need to derive more SMBH masses in various types of galaxies. ALMA will enable us to observe a large number of galaxies in a practical length of time," said Kyoko Onishi of the SOKENDAI (The Graduate University for Advanced Studies).
The findings were published in a recent edition of the Astrophysical Journal.
