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.
999 to go! A patch of the X-ray sky covering an area of about 1/1000 of the whole celestial sphere observed by eROSITA, forming part of its performance verification survey ‘eFEDS’. At the end of the 4-year all-sky survey, maps of the same quality and depth will be available for the entire sky. The image was generated from photons in the 0.5-2 keV energy range.
Credit: V. Ghirardini. MPE/IKI
999 to go! A patch of the X-ray sky covering an area of about 1/1000 of the whole celestial sphere observed by eROSITA, forming part of its performance verification survey ‘eFEDS’. At the end of the 4-year all-sky survey, maps of the same quality and depth will be available for the entire sky. The image was generated from photons in the 0.5-2 keV energy range.
Credit: V. Ghirardini. MPE/IKI
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.
Using the SRG/eROSITA all-sky survey data, scientists at the Max Planck Institute for Extraterrestrial Physics have found two previously quiescent galaxies that now show quasi-periodic eruptions. The nuclei of these galaxies light up in X-rays every few hours, reaching peak luminosities comparable to that of an entire galaxy. The origin of this…
In the first all-sky survey by the eROSITA X-ray telescope onboard SRG, astronomers at the Max Planck Institute for Extraterrestrial Physics have identified a previously unknown supernova remnant, dubbed “Hoinga.” The finding was confirmed in archival radio data and marks the first discovery of a joint Australian-eROSITA partnership established to…
Gigantic hot-gas structures above and below the galactic disc are probably due to shock waves generated by past energetic activity in the center of our Galaxy.
The project "DarkQuest: Shedding Light on the Nature of Dark Matter and Dark Energy with Multi-Wavelength All-Sky Surveys" led by Esra Bulbul at MPE is being funded by an ERC Consolidator grant for the next five years. Taking advantage of the eROSITA survey data, she aims to constrain dark energy and dark matter models.
The Sloan Digital Sky Survey’s fifth generation collected its very first observations of the cosmos at 1:47 a.m. on October 24, 2020. As the world's first all-sky time-domain spectroscopic survey, SDSS-V will provide insight into the formation and evolution of galaxies—like like our own Milky Way—and of the supermassive black holes that lurk at…
A study led by Alejandra Yrupe Fresco (Max Planck Institute for Extraterrestrial Physics) during her stay at the Instituto de Astrofísica de Canarias (IAC) has revealed the dim core and the jet structure in the nuclear region of M87, the brightest galaxy in the Virgo cluster. The observations were acquired in early April 2017, almost simultaneously…
Additional images from the first all-sky survey by the eROSITA X-ray telescope. You are free to use the images for your eROSITA reporting, please give the appropriate credit with each image.
The scientific performance demonstrated in the first weeks of operations of the eROSITA X-ray telescope promises a breakthrough in our understanding of the energetic Universe.
