About 10 billion years ago, a galaxy smashed into our cosmic home, the Milky Way, in a violent “merger” event that changed the way the Galaxy looks. Researchers from MPA together with international collaborators from the UK, Chile and Italy, have managed to piece together the impact of this event using the largest and most sophisticated simulations of the Milky Way to date. In particular, they found that the damage inflicted on the Galaxy in its youth is commensurate with a satellite that weights about a billion Suns.

Stellar clues about significant merger in the young Milky Way’s history

Warm, cold, just right? The analysis of seven strongly gravitationally lensed quasars gives new clues about the temperature of dark matter, the mysterious substance that makes up about a quarter of our universe. The results put a lower limit on the mass of a potential dark matter particle while not ruling out cold dark matter.

Taking the Temperature of Dark Matter

Magnetars are neutron stars endowed with the strongest magnetic fields observed in the Universe, but their origin remains controversial. In a study published in Science Advances, a team of scientists from CEA, Saclay,  the Max Planck Institute for Astrophysics (MPA), and the Institut de Physique du Globe de Paris developed a new and unprecedentedly detailed computer model that can explain the genesis of these gigantic fields through the amplification of pre-existing weak fields when rapidly rotating neutron stars are born in collapsing massive stars. The work opens new avenues to understand the most powerful and most luminous explosions of such stars.

A new theory of magnetar formation

A new model of galaxy formation will help scientists to better understand the distribution of gas and stars within galaxies. Researchers from the MPA in Garching, along with collborators from Switzerland, China, the UK, and Iceland have come together to release L-GALAXIES 2020, the latest version of the L-GALAXIES model project, a computational simulation designed to study many millions of galaxies simultaneously, each self-consistently evolved over billions of years of cosmic time.

L-GALAXIES 2020: Modelling millions of galaxies across billions of years

Artificial intelligence expands into all areas of the daily life, including research. Neural networks learn to solve complex tasks by training them on the basis of enormous amounts of examples. Researchers at the Max Planck Institute for Astrophysics in Garching have now succeeded in combining several networks, each one  specializing in a different task, to jointly solve tasks using Bayesian logic in areas none was originally trained on. This enables the recycling of expensively trained networks and is an important step towards universally deductive artificial intelligence.

Artificial intelligence combined

By examining the Auriga suite, a large sample of simulated Milky Way galaxies formed in the full cosmological context, scientists at MPA have been able to place constraints on the history of the Milky Way's formation. By comparing these simulations to observations of the Milky Way — and specifically to how fast stars of different metallicities in the inner regions of the Galaxy move around its centre — they were able to exclude certain formation histories. In particular they found that our galaxy had to be quite isolated with the last major merger happening over 12 billion years ago and with a galaxy less than 10% of the mass of the Milky Way.

Our Milky Way – not a typical spiral galaxy

New Hubble Constant Measurement Strengthens Discrepancy in Universe's Expansion Rate

Cosmic Magnifying Glasses Yield Independent Measure of Universe's Expansion

Rather than trying to study special regions in large-volume simulations, scientists at MPA have used the IllustrisTNG model to create whole separate universes with a modified cosmology. Their study of these separate universes shows that when the baryon density (the density of ordinary matter) changes, the number of galaxies can increase or decrease depending on how this number is measured. Also, the large-scale distribution of matter is affected by the effects of baryons, with various measures reacting differently.

Galaxy formation in separate universes

News at MPA


Note due to corona: Contacting MPA

To contain the spread of corona virus infections, the MPA has enacted certain changes to protect its employees. Wherever possible, MPA staff will work from their home offices. For the time being, the MPA will not offer public events, and its staff will not undertake travel or attend conferences. Meetings will be held via video conferencing.
Therefore it might be difficult to reach some staff members by telephone, please use Email instead. Mail continues to be received. Please note, however, that there might be some delays in getting a response.
For information about MPG research on the Corona virus, please see here:

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Springel and Hernquist receive Gruber Cosmology Prize

May 06, 2020

Volker Springel, managing director at the Max Planck Institute for Astrophysics, and Lars Hernquist, Center for Astrophysics | Harvard & Smithsonian, receive the 2020 Gruber Cosmology Prize for their defining contributions to cosmological simulations. The award recognizes their transformative work on structure formation in the universe, and development of numerical algorithms and community codes further used by many other researchers to significantly advance the field.

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SRG observatory completes X-ray map of half the sky

April 14, 2020

X-ray astronomers and astrophysicists in Russia and Germany working from their home offices with the Spectrum RG orbital observatory have reached an important milestone – the ART XC and eROSITA telescopes aboard Spectrum RG completed a map of half of the sky.

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May 2020
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"Meet the speaker'' (Zoom Meeting)

from 16:00 to 17:00

A Century of Noether's theorem

from 17:15 to 18:30

Deciphering Galaxy Formation: A combined approach from Simulations and Observations

from 11:00 to 12:00

COVID-19’s impact on museums (and other visitor attractions)

from 14:00 to 15:00

Measurement of the kinematic Sunyaev-Zel'dovich effect using Bayesian forward reconstruction of peculiar velocity

from 15:30 to 16:30

Massive discs around young stars

from 10:00 to 11:00

Ejective and Preventive: BH Feedback and its effects on the gas within and around galaxies in IllustrisTNG

from 11:00 to 12:00

Die Stringtheorie: Was ist das eigentlich?

from 19:00 to 20:30

Die Veranstaltung findet in englischer Sprache statt.

The mathematics of precision physics

from 14:00 to 15:00

The MIGHTEE Survey: Progress and Future Plans

from 15:15 to 16:00

Upcoming seminars

Massive discs around young stars

May 26, 2020 10:00 - 11:00
online only

Ejective and Preventive: BH Feedback and its effects on the gas within and around galaxies in IllustrisTNG

May 26, 2020 11:00 - 12:00
online - zoom

Die Stringtheorie: Was ist das eigentlich?

Die Veranstaltung findet in englischer Sprache statt.
May 26, 2020 19:00 - 20:30
online (siehe unten)

The mathematics of precision physics

May 28, 2020 14:00 - 15:00
online only

The MIGHTEE Survey: Progress and Future Plans

May 28, 2020 15:15 - 16:00
online only
All news

About MPA


Structure

Managing Director
Prof. Dr. Volker Springel

Scientific Members, Kollegium, Directors
Prof. Dr. Guinevere Kauffmann
Prof. Dr. Eiichiro Komatsu
Prof. Dr. Volker Springel

Emeritus Scientific Members
Prof. Dr. Wolfgang Hillebrandt
Prof. Dr. Rashid Sunyaev
Prof. Dr. Simon White

External Scientific Members
Prof. Dr. Martin Asplund
Prof. Dr. Rolf-Peter Kudritzki
Prof. Dr. Werner Tscharnuter

Head of the administration
Hendrik Wanger

Contact

Press and Public Relations
Dr. Hannelore Haemmerle
Phone: 089 30000-3980
Cornelia Rickl
Phone: 089 30000-2201
Dr. Hans-Thomas Janka
Phone: 089 30000-2228

email: pr@mpa-garching.mpg.de

Max Planck Institute for Astrophysics, Garching
Karl-Schwarzschild-Str. 1
Postfach 1317
D-85741 Garching, Germany

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