Contrast in between a traditional galaxy (ESO 325-G004) enveloped in a halo of dark matter, occupying the heaviest plate on the weight scale, and the galaxy NGC 1277 (on the left), in which the study of the mass circulation exposes the absence of dark matter. International research study led by the Instituto de Astrofísica de Canarias (IAC) and the University of La Laguna (ULL) has discovered the first proof of a huge galaxy with no dark matter. A team of scientists, led by the researcher at the IAC and the University of La Laguna (ULL) Sebastién Comerón, has actually found that the galaxy NGC 1277 does not consist of dark matter. “One is that the gravitational interaction with the surrounding medium within the galaxy cluster in which this galaxy is located has removed out the dark matter” comments Anna Ferré-Mateu, a researcher at the IAC and the ULL who likewise got involved in the study. “The other is that the dark matter was driven out of the system when the galaxy formed by the merging of protogalactic pieces, which offered increase to the relic galaxy.”.
Contrast in between a standard galaxy (ESO 325-G004) enveloped in a halo of dark matter, inhabiting the heaviest plate on the weight scale, and the galaxy NGC 1277 (on the left), in which the research study of the mass distribution reveals the absence of dark matter. Image of NGC 1277: NASA, ESA, and M. Beasley (IAC).
International research study led by the Instituto de Astrofísica de Canarias (IAC) and the University of La Laguna (ULL) has discovered the very first proof of a massive galaxy without any dark matter. The result is a difficulty to the present standard design of cosmology. The study is published in the specialized journal Astronomy and Astrophysics.
A team of scientists, led by the scientist at the IAC and the University of La Laguna (ULL) Sebastién Comerón, has found that the galaxy NGC 1277 does not include dark matter. This is the very first time that an enormous galaxy (it has a mass several times that of the Milky Way) does not show proof of this invisible component of the universe. “This outcome does not fit in with the currently accepted cosmological models, which include dark matter,” explains Comerón.
Present Cosmological Models.
In the existing standard model of cosmology, enormous galaxies contain significant amounts of dark matter, a kind of matter which does not communicate in the very same way as normal matter; the only proof for its existence is the strong gravitational pull that it applies on the stars and the gas close by, and this interaction is observable.
NGC 1277 and Relic Galaxies.
NGC 1277 is thought about a prototype “relic galaxy” which implies a galaxy that has actually had no interactions with its next-door neighbors. Galaxies of this type are extremely rare, and they are considered the remnants of huge galaxies which formed in the early days of the universe.
” The importance of relic galaxies in assisting us to understand how the first galaxies formed was the factor we chose to observe NGC 1277 with an important field spectrograph,” describes Comerón.
Comprehending the Mass Distribution.
The group produced kinematic maps from the spectra, which permitted them to establish the distribution of mass within the galaxy as much as a radius of roughly 20,000 light-years. It was identified that the mass distribution in NGC 1277 corresponded entirely to the circulation of the stars. From this, they inferred that there can not be more than 5% of dark matter within the observed radius, although the observations are constant with the complete absence of this part.
Discrepancy With Cosmological Models.
Present cosmological models anticipate that a galaxy with the mass of NGC 1277 need to have at least 10 % of their mass in the kind of dark matter, with a maximum of 70 % in this type. “This disparity in between the observations and what we would anticipate is a puzzle, and perhaps even an obstacle for the standard model” notes Ignacio Trujillo, a scientist at the IAC and the ULL, who took part in the study.
Explaining the Absence of Dark Matter.
The study proposes two possible descriptions for the lack of dark matter in NGC 1277. “One is that the gravitational interaction with the surrounding medium within the galaxy cluster in which this galaxy is located has actually removed out the dark matter” remarks Anna Ferré-Mateu, a researcher at the IAC and the ULL who likewise took part in the study. “The other is that the dark matter was eliminated of the system when the galaxy formed by the merging of protogalactic pieces, which offered rise to the relic galaxy.”.
Staying Questions.
Neither of these descriptions fully pleases the authors of the research study, “so the puzzle of how a massive galaxy can form without dark matter remains a puzzle” firmly insists Comerón. In order to continue looking into the secret the team prepares to make brand-new observations with the WEAVE instrument on the William Herschel Telescope (WHT) at the Roque de los Muchachos Observatory, in the Canary Island of La Palma.
Implications on Dark Matter Theories.
If this the result, that NGC 1277 does not have dark matter, is validated, it would cast strong doubt on alternative models for dark matter, specifically theories in which gravity is modified and the significant part of the gravitational destination within galaxies is due to a minor change in the law of gravity on big scales. “Although the dark matter in a particular galaxy can be lost, a customized law of gravity should be universal, it can not have exceptions, so that a galaxy without dark matter is a refutation of this kind of alternative to dark matter,” notes Trujillo.
Reference: “The enormous relic galaxy NGC 1277 is dark matter lacking: From dynamical designs of integral-field stellar kinematics out to 5 efficient radii” by Sébastien Comerón, Ignacio Trujillo, Michele Cappellari, Fernando Buitrago, Luis E. Garduño, Javier Zaragoza-Cardiel, Igor A. Zinchenko, Maritza A. Lara-López, Anna Ferré-Mateu and Sami Dib, 11 July 2023, Astronomy and Astrophysics.DOI: 10.1051/ 0004-6361/2023 46291.
