With the start of the SRG all-sky survey, eROSITA promises most accurate maps of the X-ray sky ever
December 08, 2019
Launched from Baikonur on July 13th 2019 to the second Sun-Earth Lagrange point (L2), the Russian-German SRG mission has now started its main task. On December 8th, after an extensive program of commissioning, calibration and performance verification of its two X-ray telescopes (ART-XC and eROSITA), the satellite has begun observing the sky in continuous scanning mode. As SRG follows the revolution of Earth, and hence also of the L2 point, around the Sun, it will perform eight complete surveys of the whole sky, one every six months, for the next 4 years. Pre-launch predictions suggest that, over that time, the eROSITA instrument, conceived, designed and built at MPE, should discover approximately 100,000 clusters of galaxies, around 3 million accreting supermassive black holes and half a million active stars.
To confirm those predictions for the all-sky survey, eROSITA scientists have performed a number of test observations over the past few weeks. Among those, a mini-survey called eFEDS (eROSITA Final Equatorial Depth Survey) was devised in order to image a small patch of the sky to the same depth expected at the end of the 4-years all-sky survey. The eFEDS data show the same stunning image quality demonstrated by the eROSITA first light (see also IKI press-release featuring more eROSITA images of the Lockman Hole and the Galactic Plane). More importantly, they allowed the scientists to confirm with great accuracy the sensitivity of the X-ray telescope to its main target classes.
Over an area of just 1/300 of the full sky, eROSITA revealed more than 18,000 point-like X-ray sources, around 85% of them being distant Active Galactic Nuclei (AGN) harboring growing supermassive black holes, and most of the remainder X-ray stars. The mini-survey also discovered more then 400 clusters of galaxies (including a few at a redshift around 1), easily recognizable from their extended, diffuse morphology in the sharp X-ray images (see image).
It took around 4 days of eROSITA observations to generate these maps, and it will take about 1500 more to make such exquisite maps for the whole sky. The main goal of the SRG/eROSITA all-sky survey is to use these maps to study the large-scale structure of the Universe, and to measure its expansion rate by counting clusters of galaxies and the distribution of AGN in space and time. At the same time, eROSITA will reveal a large population of hot stars, neutron stars and stellar mass black holes scattered around the body of our Milky Way.
The commissioning phase of the eROSITA X-ray telescope aboard the SRG spacecraft has just been completed. During this phase, all seven eROSITA cameras have been switched on individually, and demonstrated performance satisfying the mission requirements. As of Sunday 13 October 2019, all seven telescope modules are operating simultaneously, and eROSITA has entered full science operations, beginning with the calibration and performance verification (CalPV) phase. Early images and results from eROSITA will be presented at a “first light” symposium to be held at MPE in the afternoon of Tuesday October 22nd. Interested members of the media should contact Hannelore Hämmerle (see side column) for more details.
The SRG (Spektrum-Roentgen-Gamma) Orbital Observatory has recently started one of its many tests by looking at a small patch of the extragalactic sky with one of the seven eROSITA telescope modules. The results are consistent with preflight expectations. The work on commissioning other modules is still underway and will be completed in the coming weeks before starting a 4-year long all-sky survey later this year.
On 25 April 2019, the Spektr-RG Space Observatory was transported to the Baikonur Cosmodrome - the final stage in preparation for its launch on 21 June. Spektr-RG carries the X-ray telescope eROSITA, which was developed and built at MPE. Its aim is to perform a highly sensitive survey of the entire sky in X-ray light, once it arrives at its observation point L2.
Outflows of matter and energy from a galaxy’s centre are considered key players in the formation and evolution of galaxies and other structures in the Universe. Astronomers led by the Max Planck Institute for Extraterrestrial Physics have now created the most extensive X-ray map of the central degrees of the Milky Way, thereby discovering a channel of X-ray emitting gas connecting the Milky Way centre to structures much further out.
On June 11, NASA’s Fermi Gamma-ray Space Telescope celebrates a decade of using gamma rays, the highest energy form of light in the universe, to study black holes, neutron stars, and other extreme cosmic objects and events. MPE scientists use data from both instruments on-board Fermi, one of which was built jointly by MPE and other institutes.
The next generation of the Sloan Digital Sky Survey (SDSS-V) will move forward with mapping the entire sky following a $16 million grant from the Alfred P. Sloan Foundation. The grant will kickstart a ground-breaking all-sky spectroscopic survey for a next wave of discovery, anticipated to start in 2020, just after the start of the all-sky survey by the MPE’s eROSITA X-ray telescope.
Simultaneous detections of a short Gamma-Ray Burst by Fermi/GBM, INTEGRAL, and as gravitational wave by LIGO/Virgo, followed by MPG/GROND multi-wavelength observations heralds the start of a new era in astronomy
The National Academy of Sciences Leopoldina honors Joachim Trümper, Director Emeritus at the MPE, with the Cothenius Medal for his outstanding scientific lifetime achievement. The award will be presented to Joachim Trümper at the opening ceremony of the Annual General Meeting of the Leopoldina on Friday, 22 September 2017, in Halle (Saale).
On the 23rd of June, the amateur satellite "MaxValier Sat" was successfully launched into an Earth orbit on an Indian rocket. On board: the miniature X-ray telescope μROSI, which was built by the Max Planck Institute for Extraterrestrial Physics in Garching. Intensive work had been carried out in South Tyrol, Munich and Bremen to get all instruments ready. The MaxValier satellite is a unique cooperation between academic research, the aerospace industry and the commercial schools in Bolzano and Merano. The aim of the mission is to provide a complete survey of the sky in soft X-rays – with the data being broadcast to amateur astronomers - as well as observing the Earth’s upper atmosphere to discover an oxygen absorption line.
CNES President Jean-Yves Le Gall and Kirpal Nandra, Managing Director of the Max Planck Institute for Extraterrestrial Physics (MPE), have signed a memorandum of understanding on Germany’s contribution to the MXT and ECLAIRs instruments that CNES is developing for the French-Chinese SVOM astronomy mission.
In 1995, a paper was published about ROSAT observations of dust scattering halos, which has now reached more than 1000 citations. This makes it the top ranking paper under more than 9000 publications that mainly deal with the “hot” topics in astrophysics, such as supernovae, neutron stars, black holes, quasars or galaxy clusters. Why did a side issue such as interstellar dust receive so much attention?