Black hole at the core of a galaxy periodically brightens up

X-ray Quasi-Periodic Eruptions (QPEs) from the black hole at the core of GSN 069 as observed with XMM-Newton and Chandra. In each panel, the X-ray amplitude is relative to the ‘quiescent’ level. [credit: G. Miniutti, CAB]

During an ESA’s XMM-Newton observation on 2018 Christmas Eve, an international team led by Giovanni Miniutti, of the Centro de Astrobiología (CAB, CSIC-INTA) in Madrid, discovered some mysterious flashes from the active black hole at the core of the galaxy GSN 069, about 250 million light years away. X-ray emission from the center of that galaxy was seen to suddenly increase its brightness by up to a factor 100, then dimmed back to its normal levels within one hour and lit up again nine hours later. Giant black holes regularly flicker like a candle but the rapid, repeating changes seen in GSN 069 had never been observed before from supermassive black hole at the core of galaxies.

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Video presentation of the X-IFU instrument of the Athena mission

The X-ray Integral Field Unit (X-IFU) is the cryogenic micro-calorimeter of the Athena space X-ray observatory, the second large mission of the Cosmic Vision Program of the European Space Agency, selected to explore the scientific theme “The Hot and Energetic Universe”. It is designed to 1) study the dynamical, physical and chemical properties of hot plasmas, as those found in clusters of galaxies, and 2) study black hole accretion disks, jets, outflows and winds from galactic stellar mass black holes to the super-massive ones found in active galactic nuclei. With its unprecedented capabilities, it is also the prime instrument for many Athena observatory science targets, such as planets, stars, supernovae, compact objects, interstellar medium among many other scientific topics.

X-IFU is a cryogenic imaging spectrometer, offering spatially-resolved high-spectral resolution X-ray spectroscopy over a 5 arc minute equivalent diameter field of view with spectral resolution of 2.5 eV up to 7 keV. The breadth of the science affordable with the X-IFU encompasses key scientific issues of the Hot and Energetic Universe science theme and beyond.

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The centre of the galaxy NGC 5643 has been chosen as an ESO Picture of the Week

Centre of NGC 5643 observed by ALMA and VLT. Credit: ESO/A. Alonso-Herrero et al.; ALMA (ESO/NAOJ/NRAO)

This ESO Picture of the Week shows the centre of a galaxy named NGC 5643. This galaxy is located 55 million light-years from Earth in the constellation of Lupus (The Wolf), and is known as a Seyfert galaxy. Seyfert galaxies have very luminous centres — thought to be powered by material being accreted onto a supermassive black hole lurking within — that can also be shrouded and obscured by clouds of dust and intergalactic material. Continue reading

The James Webb Space Telescope (JWST) passes another milestone

NASA’s James Webb Space Telescope is unloaded from a U.S. military C-5 Charlie aircraft at Los Angeles International Airport (LAX) on Feb. 2, 2018. Credits: NASA/Chris Gunn

The optics and scientific instrumentation (OTIS) of JWST arrived yesterday in the facilities
of Northrop Grumman in California, where the rest of the spacecraft (solar shields, communication elements, etc) is already. The OTIS passed the final performance tests
last year at NASAS’s Johnson Space Center in Houston, Texas. The spacecraft bus
and solar shields still need to perform a series of tests before the integration, however. Continue reading

James Webb Space Telescope MRS working group meeting

The MIRI Medium-Resolution Spectrometer (MRS) is the only mid-IR Integral Filed Spectrograph on board the James Webb Space Telescope. It offers integral field spectroscopy at resolutions up to ~4000, between 4.9 and 28.8 μm using four different nested Integral Field Units up to 7.2″ × 7.9″ in size. This workshop is part of a series of conferences of meetings of the international MRS testing and calibration working group. With these periodic workshops we define commissioning activities and calibration products to deliver to guarantee the best scientific return of MRS. Continue reading

A 100 kpc nebula associated with the “Teacup” fading quasar

HST image and GTC/OSIRIS spectra of the “Teacup” containing the Hα+[NII] lines. We highlight prominent emission line features such as the NE and SW bubbles. For further details, see Villar-Martín et al. 2017.

The “Teacup” (SDSS J143029.88+133912.0 at z=0.085) is a nearby quasar, whose nickname comes from the peculiar morphology of the extended ionized gas. It shows a loop-shaped structure reminiscent of a teacup “`handle” which extends up to ~12 kpc (~39,000 light years) NE of the active galactic nucleus. Continue reading

First detection of the 448 GHz H2O transition in space

Left: Map of the 448 GHz (rest frequency) continuum (top panel) and zeroth moment of the H2O 423 − 330 emission (bottom panel) of ESO 320-G030. Right: Continuum subtracted profile of the H2O 423 − 330 448 GHz emission. See Pereira-Santaella et al. 2017 for further details.

Water is a key molecule to probe dense and warm regions in the interstellar medium, because of its chemistry as well as its coupling to the far-infrared. This work presents the first detection of the ortho-H2O 4_23 – 3_30 transition at 448 GHz in space. Continue reading

The response of relativistic outflowing gas to the inner accretion disk of a black hole

Artist impression illustrating a super-massive black hole with X-ray emission emanating from its inner region (pink) and ultrafast winds streaming from the surrounding disk (purple). Credit: ESA

Active Galactic Nuclei (AGN) are thought to have a profound effect on large scales through feedback mechanisms. AGN gas outflows release vast amounts of energy into the interstellar medium and can clear out the surrounding gas, possibly regulating star formation in the host galaxy as well as preventing further gas accretion onto the black hole. Such feedback may well contribute to the intimate observed relationship between the central black hole and the host galaxy properties.

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Molecular gas in the halo fuels the growth of a massive cluster galaxy at high redshift

 

Molecular gas on multiple scales in the Spiderweb galaxy

The largest galaxies in the universe reside in galaxy clusters. Using sensitive observations of carbon monoxide, we show that the Spiderweb galaxy—a massive galaxy in a distant protocluster—is forming from a large reservoir of molecular gas. Most of this molecular gas lies between the protocluster galaxies and has low velocity dispersion, indicating that it is part of an enriched intergalactic medium. This may constitute the reservoir of gas that fuels the widespread star formation seen in earlier ultraviolet observations of the Spiderweb galaxy. Our results support the notion that giant galaxies in clusters formed from extended regions of recycled gas at high redshift.