#microquasar

GRS 1915+105 is at it again

Many years ago I made a post about how weird the stellar black hole GRS 1915+105 is.

Well, now there is another potential way it is weird...it might be forming stars.

See that curved feature up there? That's a bow shock, created when the black hole's jet impacts the gas between the stars.

In the middle of the bow shock is an infrared source that most likely is a dense cloud of gas with massive stars forming inside.

The jet carves cavities in the gas between the stars. This could potentially reduce the amount of gas that is available for star formation. But at the front of the jet, gas is compressed, potentially causing it to collapse and fragment into stars.

This sort of process has been observed many times in supermassive black holes.

But now I realize feedback from stellar black holes might also be important. So crazy.

Citation: Motta, S. E., Atri, P., James, Matthew H., et al. 2025, Astronomy and Astrophysics, article ID A222

The figures are Fig 1, Fig 2, and Fig 3 from this paper.

(ESA/Hubble)  GRO J1655-40 is the second so-called 'microquasar' discovered in our Galaxy. Microquasars are black holes of about the same mass as a star. They behave as scaled-down versions of much more massive black holes that are at the cores of extremely active galaxies, called quasars. Astronomers have known about the existence of stellar-mass black holes since the early 1970s. Their masses can range from 3.5 to approximately 15 times the mass of our Sun. Using Hubble data, astronomers were able to describe the black-hole system. The companion star had apparently survived the original supernova explosion that created the black hole. It is an ageing star that completes an orbit around the black hole every 2.6 days. It is being slowly devoured by the black hole. Blowtorch-like jets (shown in blue) are streaming away from the black-hole system at 90% of the speed of light.

Credit: European Space Agency, NASA and Felix Mirabel (the French Atomic Energy Commission & the Institute for Astronomy and Space Physics/Conicet of Argentina)

The Tulip and Cygnus X-1 

Framing a bright emission region, this telescopic view looks out along the plane of our Milky Way Galaxy toward the nebula rich constellation Cygnus the Swan. Popularly called the Tulip Nebula, the reddish glowing cloud of interstellar gas and dust is also found in the 1959 catalog by astronomer Stewart Sharpless as Sh2-101. About 8,000 light-years distant and 70 light-years across the complex and beautiful nebula blossoms at the center of this composite image. Ultraviolet radiation from young energetic stars at the edge of the Cygnus OB3 association, including O star HDE 227018, ionizes the atoms and powers the emission from the Tulip Nebula. HDE 227018 is the bright star near the center of the nebula. Also framed in the field of view is microquasar Cygnus X-1, one of the strongest X-ray sources in planet Earth's sky. Driven by powerful jets from a black hole accretion disk, its fainter visible curved shock front lies above and right, just beyond the cosmic Tulip's petals.

Il #buconero in #V404Cygni ha mostrato qualcosa di mai visto prima, getti relativistici che vengono sparati a brevi intervalli in tutte le direzioni.

V404 Cygni è un microquasar, cioè un oggetto celeste che ha molte delle caratteristiche di un quasar (emissioni radio forti e variabili osservate spesso come dei getti radio e un disco di accrescimento attorno a un buco nero) ma a differenza di un quasar il buco nero non è uno di quelli supermassicci che di solito troviamo nei centri galattici. Il buco nero in V404 Cygniè uno degli oggetti più…

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Quel microquasar spara antimateria

Un team internazionale di ricercatori ha condotto osservazioni alle alte energie del microquasar V404 Cygni durante il suo recente picco di attività. I dati, pubblicati su Nature, mostrano un chiaro eccesso d’emissione oltre i 500 mila elettronvolt. Un team internazionale di ricercatori è riuscito a osservare, per la prima volta con chiarezza inequivocabile, la presenza di plasma di elettroni e…

A GRS 1915+105 VALENTINE

In case you haven’t already noticed, I have a soft spot for microquasars. The little guys are just so cute! Trying to imitate AGN...just kidding. They’re actually badass. 

Case in point: GRS 1915+105. This whirling beast literally swallows its food faster than its own radiation should blow it away (super-Eddington accretion) and spits out bullets of matter at relativistic speed. It’s like a black hole minigun! (though amongst stellar black holes it is not so mini. Maybe like 15 or even 18 solar masses. Quite large for a stellar black hole.)

And yet, it also is kind of a romantic. For you see, GRS 1915+105 has an x-ray emission pattern called the “heartbeat” state, because it ticks off little bursts of x-rays that look just like an EKG. 

So maybe it is also looking for love...

HAPPY VALENTINE’S DAY!