Cosmological simulations show that the growth of galaxies in the early Universe is regulated by the interplay between gas accretion onto dark-matter halos and ejection of matter by stars and active galactic nuclei (AGN). While these processes are routinely described in theoretical works, still little is known from observations on the complex exchanges of mass and energy within the halos of galaxies, where large-scale infall (i.e. accretion) meets outflows (i.e. ejection). Recently, an international team of astronomers was able to probe the halo gas of a massive galaxy system, SMM J02399-0136, using a novel approach. These observations unveiled – for the first time – the infall towards the galaxies of a large mass of diffuse, highly turbulent multiphase gas, pervaded by powerful outflows and more than 10 times larger than the star-forming galaxies.

Probing the interface between infall and outflows in a high-redshift massive halo
The record sensitivity of the X-ray survey performed by the Spektrum-Roentgen-Gamma Observatory makes it possible to discover very rare and unusual X-ray sources. After the recently completed third all-sky survey, astronomers identified a gigantic, “round” object, named G116.6-26.1, with an angular size of 8 times the Moon or a physical size of truly astounding 600-700 light-years. The authors of the discovery believe this to be the remnant of a thermonuclear supernova, which exploded some 40,000 years ago. The source is located high above the plane of our Galaxy, most likely in the hot, low density gas of the Milky Way halo. Such an unusual environment makes the remnant almost ten times brighter in X-rays than naive models would predict. This and similar remnants (if more are to be found) open a new way of probing the elusive hot gaseous halo of our Galaxy.

Newly discovered supernova remnant as a probe of the hot gas in the Milky Way halo
Astronomers have made the rare sighting of two stars spiralling to their doom by spotting the tell-tale signs of a teardrop-shaped star. The tragic shape is caused by a massive nearby white dwarf distorting the star with its intense gravity, which will also be the catalyst for an eventual supernova that will consume both.

Teardrop shape reveals supernova fate
The gas in and around galaxies can be probed with absorption line studies using light from background quasars. Scientists at MPA have now used a large sample from the SDSS DR16 to automatically detect absorbers in background quasars and connect them with foreground galaxies. Their analysis shows that cool circumgalactic gas has a different physical origin for star-forming versus quiescent galaxies.

The cool circumgalactic medium in SDSS galaxies
Some of the most energetic radiation that reaches Earth comes from an exploded star in our Galaxy. An international team of researchers was now able to measure the distance to this object using an adjacent dust cloud with much higher degree of precision than ever before. This is the first step in better understanding the energetic processes that are going onin this supernova remnant.

Dust cloud determines distance
Magnetic fields are ubiquitous in the Universe today, from stars to clusters of galaxies. Their origin, however, remains a mystery. MPA researchers have now simulated in great detail a variety of proposed mechanisms for magnetogenesis – i.e. how magnetic fields might be created – in high-redshift galaxies. They also studied their impact on the formation and evolution of galaxies, providing guidance to both future observations and simulations. Their work demonstrates that high-redshift galaxies may hold the key to understanding the origin of cosmic magnetic fields. It also provides the first-ever investigation on galactic scales of a novel magnetogenesis mechanism.

Magnetogenesis around the first galaxies and its impact on galaxy formation
Intermediate mass black holes (IMBH) should be linking observed stellar black holes and supermassive black holes, but their formation mechanisms are still debated. Young and dense massive star clusters are promising environments for the formation of such black holes through collisions. An international team lead by MPA researchers has presented novel realistic simulations of star clusters, where these missing links form by rapid collisions of stars and black holes. The study also predicts an IMBH formation channel by the merging of black holes in a mass regime, which is excluded by stellar evolution models. In this “mass gap” a black hole merger has indeed been observed recently by the LIGO/Virgo gravitational wave collaboration.

The formation of intermediate mass black holes in young massive star clusters
Where are the baryons? This question naturally arises as the predicted abundance of baryons in the universe - the basic building blocks of all elements in the periodic table – do not agree with observations of the intergalactic medium. Locating the missing baryons will help us to not only better understand the formation and evolution of galaxies, but also to better constrain possible extensions of the current standard model of cosmology. MPA researchers have turned to a novel approach in modelling the galaxy distribution to optimize measurements of the kinematic Sunyaev-Zel'dovich effect, an emerging tool to probe the distribution of baryons in galaxy clusters.

Optimal measurements of the kinematic Sunyaev-Zel'dovich effect reveal missing matter

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. (Large) public events continue to be suspended; external guests are subject to the 3G rule and need to proof their compliance on entering the MPA building.
It might be difficult to reach some staff members by telephone, please use email instead.
For information about MPG research on the Corona virus, please see here:
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Physics vs. Piano
 

September 14, 2021
Instead of following a musical career, MPA postdoc Tiara Battich is investigating the processes inside hot sub-dwarf stars
 
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Shaking stars to get to their cores

August 23, 2021
Benard Nsamba receives prestigious fellowship to study stars and inspire Ugandan students
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September 2021
Mon Tue Wed Thu Fri Sat Sun
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Planets of Cool Stars and the PLATOspec Project

from 11:00 to 12:00

Zoom link changed!

From Astrophysics to Ntuity, a renewable energy platform

from 17:00 to 18:00

Pinpointing fast radio bursts in space and time

from 15:15 to 16:15

The role of turbulence, cooling and stratification in the intracluster medium

from 11:00 to 12:00

A Journey across Hertzsprung-Russel diagram with 3D hydrodynamical simulations of cool stars

from 15:30 to 16:30

The impact of turbulence properties on grain growth in protoplanetary disks

from 10:00 to 11:00

Evolution mapping: a new approach to describe matter clustering in the non-linear regime

from 11:00 to 12:00

Chasing Radio Galaxies Across the Universe

from 12:00 to 13:00

Chemo-dynamical mapping of the Galactic bulge with RR Lyrae stars

from 10:45 to 11:45

The young protostellar disk in IRAS16293-2422 B is hot and shows signatures of gravitational instability

from 15:00 to 16:00

please note the unusual time

Upcoming seminars

Chemo-dynamical mapping of the Galactic bulge with RR Lyrae stars

Sep 22, 2021 10:45 - 11:45
ESO Headquarters, Garching, Room: online only

The young protostellar disk in IRAS16293-2422 B is hot and shows signatures of gravitational instability

please note the unusual time
Sep 22, 2021 15:00 - 16:00
MPE, Room: online - zoom

Job Offers

PostDoc Position (m/f/d) in the "Learning the Universe" Collaboration
at the Max-Planck-Institute for Astrophysics, Garching near Munich, Germany

 

September 22, 2021

MPA Postdoctoral Fellowships in Astrophysics

September 08, 2021
All news

About MPA

Structure

Managing Director
Prof. Dr. Volker Springel

Scientific Members, Kollegium, Directors
Dr. Selma E. de Mink
Prof. Dr. Guinevere Kauffmann
Prof. Dr. Eiichiro Komatsu
Prof. Dr. Volker Springel

Emeritus Directors
Prof. Dr. Wolfgang Hillebrandt
Prof. Dr. Rashid Sunyaev
Prof. Dr. Simon White

External Scientific Members
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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