Scientists Observe 5,000 Nearby Galaxies through MaNGA

Scientists Observe 5,000 Nearby Galaxies through MaNGA

Scientists Observe 5,000 Nearby Galaxies through MaNGA
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The analysis of the first 3 years of the Mapping Nearby Galaxies (MaNGA) program gave some important insights about 5,000 nearby galaxies.

The latest data release from the Sloan Digital Sky Survey (SDSS) explained the observations of MaNGA during the first three years of its operation. It uses a specific method called Resolved Spectroscopy, which enables this program to examine galaxies in greater detail than previous surveys. Kevin Bundy, the Principal Investigator of MaNGA who serves as an Adjunct Professor of Astronomy and Astrophysics at UC Santa Cruz, talked about the efficiency of this technique in the following words:

“Resolved spectroscopy allows us to dissect a galaxy and study its internal composition and the motions of its stars and gas. People have been doing resolved spectroscopy for individual galaxies, but we’ve never had it for thousands of galaxies, so MaNGA gives us the statistical power to address a lot of important questions.”

Spectroscopy has always been a powerful tool for astronomical studies because it can measure the amount of light emitted by an object at different wavelengths. Previously, only one spectrum was obtained for each galaxy but resolved spectroscopy results in hundreds of separate spectra as they cover every location within the galaxy.

The MaNGA program used 2 BOSS spectrographs at the 2.5-meter Sloan Foundation Telescope at Apache Point Observatory. The special design of these spectrographs enables them to measure the spectra at multiple points in the same galaxy. Its spectra provide continuous coverage from optical to near-infrared wavelengths.

Basic Goal of MaNGA

The primary purpose of MaNGA is to understand the complete history of present-day galaxies. It includes details of each phase beginning from their birth to their death from quenching of star formation. The researching team found evidence for outflows of hot ionized gas in dead galaxies, which strengthened the idea that the powerful winds (produced by the central black hole of a galaxy) can bring an end to the star-forming capabilities of the galaxy. Similarly, researchers are also trying to determine the assembling mechanisms of these nearby galaxies by examining the chemical signatures of stars in different parts of galaxies.

Bundy mentioned that MaNGA will analyze a representative sample of about 10,000 nearby galaxies in the 4th phase of SDSS. He acknowledged that they have completed more than half of their journey and will hopefully reach their target by 2020. The importance of MaNGA can be judged by the fact that the data from more than 4,600 nearby galaxies is now publicly available. Bundy praised this amazing survey by saying,

“This data release is a major milestone for us. MaNGA is already by far the largest survey of its kind, and this release includes both the data and the analytical tools the project has developed.”


The data of MaNGA and resulting galaxy maps were accessed by making use of a new, powerful interface known as Marvin. It has a wide range of tools for searching, accessing, and visualizing data and provide an immense variety of information about each galaxy. Some of the key features include stellar motion, star formation, and emission lines. The data analysis pipeline that produced all these amazing data products was led by a Project Scientist at UC Observatories, Kyle Westfall.

MaNGA Stellar Library

What made this data release even more significant is the MaNGA Stellar Library, which contains spectra of more than 3,000 stars in the Milky Way. Renbin Yan, the Survey Scientists of MaNGA from the University of Kentucky, led the development of this library. According to an estimate, this library will ultimately store data of about 5,000-6000 stars. These spectra are incredibly useful for researchers because they can try to reconstruct the spectrum of a galaxy by using these individual stars. Consequently, they can determine different kinds of stars present in the galaxy. Bundy referred to that and said,

“The MaNGA Stellar Library is the largest library of stars ever compiled, with spectra from the same instruments used for the galaxies, so it’s a very powerful tool for understanding the nature of the stellar populations in these galaxies.”

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