Recent Comments

    Category Astronomy/Space

    Rare Encounters between Cosmic Heavyweights

    August 31, 2020, Categories  Astronomy/Space

    SDSS J141637.44+003352.2, a dual quasar at a distance for which the light reaching us was emitted 4.6 billion years ago. The two quasars are 13,000 light years apart on the sky, placing them near the center of a single massive galaxy that appears to be part of a group, as shown by the neighboring galaxies in the left panel. In the lower panels, optical spectroscopy has revealed broad emission lines associated with each of the two quasars, indicating that the gas is moving at thousands of kilometers per second in the vicinity of two distinct supermassive black holes. The two quasars are different colors, due to different amounts of dust in front of them. Credit: Silverman et al.

    Maunakea observatories discover three pairs of merging supermassive blackholes...

    Read More

    Hubble Maps Giant Halo around Andromeda Galaxy

    August 30, 2020, Categories  Astronomy/Space

    This illustration shows the location of the 43 quasars scientists used to probe Andromeda’s gaseous halo. These quasars—the very distant, brilliant cores of active galaxies powered by black holes—are scattered far behind the halo, allowing scientists to probe multiple regions. Looking through the immense halo at the quasars’ light, the team observed how this light is absorbed by the halo and how that absorption changes in different regions. By tracing the absorption of light coming from the background quasars, scientists are able to probe the halo’s material.
    Credits: NASA, ESA, and E. Wheatley (STScI)

    In a landmark study, scientists using NASA’s Hubble Space Telescope have mapped the immense envelope of gas, called a halo, surrounding the Andromeda galaxy, our nearest large g...

    Read More

    New observations of Black Hole devouring a Star Reveal Rapid Disk Formation

    August 28, 2020, Categories  Astronomy/Space

    tde-simulation-450.jpg
    This image from a computer simulation shows the rapid formation of an accretion disk during the disruption of a star by a supermassive black hole. (Image credit: Jamie Law-Smith and Enrico Ramirez-Ruiz)

    When a star passes too close to a supermassive black hole, tidal forces tear it apart, producing a bright flare of radiation as material from the star falls into the black hole. Astronomers study the light from these “tidal disruption events” (TDEs) for clues to the feeding behavior of the supermassive black holes lurking at the centers of galaxies.

    New TDE observations led by astronomers at UC Santa Cruz now provide clear evidence that debris from the star forms a rotating disk, ie an accretion disk, around the black hole...

    Read More

    Galactic Bar Paradox Resolved in Cosmic Dance

    August 27, 2020, Categories  Astronomy/Space

    Snapshots from a Milky Way galaxy simulation. The bar in the centre and the spiral arms are thought to rotate at different speeds. If they are disconnected the bar shows its true and smaller structure (left). Every time they meet, the bar appears longer and its rotation slower (right).
    Credit T. Hilmi / University of Surrey
    Licence type Attribution (CC BY 4.0)

    New light has been shed on a mysterious and long-standing conundrum at the very heart of our galaxy. The new work offers a potential solution to the so-called ‘Galactic bar paradox’, whereby different observations produce contradictory estimates of the motion of the central regions of the Milky Way. The results are published in Monthly Notices of the Royal Astronomical Society.

    The majority of spiral galaxies, like our home the ...

    Read More