Stunning beauty of a voorwerp!

Simbad describes this galaxy as a BL Lacertae - type object.

BL Lacertae object - Wikipedia.

I think this galaxy is surrounded by several voorwerpjes (reflection nebulae) It is one of the most beautiful I ever have seen! :heart_eyes::star_struck:

Ine :stars::dizzy:


That’s beautiful! DESI has two spectra – one of the galaxy core, and one of that bright blue reflection nebula! Tons of bright emission lines!

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What an amazing object and wonderful discovery Ine. Sorry long - I am placing this here

From the paper:

I find it weird that these nebula are all over the place! If caused by jets… hmm those lines are radio contours… I wish they were clearer in the difference between “jet” and “lobe”
But I suppose they think that those dark blue regions are reflection nebula but also regions of star formation, triggered by the jet, called knots.

“A cloud overtaken by shocks breaks up into dense fragments that are Jeans unstable, and might form stars. It then appears that the shocks produced by the expansion of the radio lobes are causing the formation of new stars. Star formation requires the presence of dense clouds of cold gas.”

They go over more here in an interesting set of diagrams that look at certain emission ratios, it’s over my head, but it may be under one of yours :slight_smile:

The red arrows indicate the knots of star formation, the gray circles where they took spectroscopy. So I suppose that means no star-formation knots in the other places.


Another object where similarly star formation is thought to occur, triggered from a radio source


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The galaxy you mention above is no #voorwerp but a #Minkowski object. It is well-known.

Ine :stars::dizzy:

Thank you for keeping me on my toes! It is Minkowski’s object, who is minkowski anyways, is that the same Minkowski of Minkowski spacetime? But isn’t Minkowski’s object also a #voorwerp? So as far as I can tell for something to be a voorwerp, it is: a region of reflection nebula, housing star formation, caused by an astophysical jet, set apart in a region away rom the galaxy. I wonder if there is a catalogue of galaxies which are facing down jets, and what that does to their evolution.

I want to understand these Baldwin, Phillip, Terlevich diagrams.

OxygenIII in Hanny’s Voorwerp

Minkowski's Object (Arp 133).
Minkowski’s Object (Arp 133) is a peculiar dwarf galaxy in the constellation Cetus lying about one arc-minute ENE of the elliptical galaxy NGC 541. The latter is also a radio galaxy that has a jet of ionized plasma emanating from its nucleus. Evidence now suggests that a burst of star formation in Minkowski’s Object (Arp 133) was actually triggered by the jet from the nucleus of NGC 541 because the body of the jet can be traced all the way to the region where the new stars are forming. If this turns out to be true, it will be the first known case of a jet from one galaxy influencing a neighboring galaxy and triggering new star birth. The details of just how this could occur are uncertain."


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