Disturbing the Universe

David L Clements, science and science fiction


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Supermassive black hole eats a star – and we see it!

Thirteen years ago, my colleague Prof Peter Meikle came into my office and asked “Dave, you know something about merging galaxies?”

“Yes,” I replied.

“Well,” he said, “something odd has happened in Arp 299.”

Arp 299 is a merger between two galaxies which has resulted in a burst of star formation and fuel falling onto the supermassive black hole in at least one of the galactic nuclei. What Peter had found was that one of the galactic nuclei had suddenly got much brighter in the near-infrared, but this was not visible at optical wavelengths. This meant that whatever had happened was enshrouded by a lot of dust so that only longer wavelength radiation from the event could reach us.

What ensued was a campaign using many telescopes on the ground and in space to monitor this event and try to work out what was causing it.

At first we thought it was a dust enshrouded supernova, which is understandable given the starburst going on in Arp299, but as time wore on, and the nucleus continued to shine brighter in the near-infrared, it became clear that whatever the power source might be, it was more powerful than even a luminous supernova.

Eventually Seppo Matilla, who was leading the project, got some deep high resolution radio observations which showed a new jet of radio emission in this nucleus. This is a clear signature of emission from a supermassive black hole, and the energetics suggested that a star about twice the mass of the sun was being ripped apart and swallowed by a supermassive black hole in this nucleus, with about 20 million times the mass of the sun. This is what is known as a Tidal Disruption Event.

You can read more about this on Imperial’s website:

https://www.imperial.ac.uk/news/186671/scientists-spot-erupting-jets-material-black/

and can also see our actual paper in Science:

http://science.sciencemag.org/content/early/2018/06/13/science.aao4669

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Yet more sexual harassment in Astronomy

I’m glad that more details on this case are now public, including the name of the perpetrator, Dr Filipe Abdalla. UCL’s actions in this case are also reprehensible.

Let’s hope that google searches on the name Dr Filipe Abdalla will soon have the details of his sexual harassment coming up on top.

In the Dark

Yesterday I saw a thread on Twitter commencing with the following tweet by Dr Emma Chapman (now of Imperial College):

You can find the whole thread here; and here is one of the documents that have now been published:

I have met Dr Chapman and knew that she had endured sexual harassment in the recent past, but did not know any of the details of her case because they remained confidential until yesterday. They relate to sexual harassment by her PhD supervisor, Dr Filipe Abdalla of University College London (whom I don’t know personally). It has taken Dr Chapman two years to get documents relating to this case discosed publicly. I also didn’t realise that episodes of harassment of other women was involved or that Dr Abdalla, who remains in post at UCL, has apparently been indulging in retaliatory behaviour towards those who have made compaints against his conduct.

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Strike Days

I will also be taking part in the strike action discussed here by Peter Coles.

In case you weren’t aware, from tomorrow (22nd February) the University and College Union (UCU) is taking industrial action over proposed drastic cuts to staff pensions funded by the Universities Superannuation Scheme (USS). You can find some background to the pensions dispute here (and in related articles). A clear explanation of why the employers’ justification for […]

via UCU Strike Action — In the Dark


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Books Read 2017 – Part 2

The Stars are Legion – Kameron Hurley

Fun and very different space opera. Lots of squishy biological stuff.

Roboteer – Alex Lamb

Another space opera, with a nasty oppressive Earth empire against the genetically modified.

The Left Hand of Darkness – Ursula K Le Guin

A classic, and deservedly so.

Hyperobjects – Timothy Morton

I don’t usually read philosophy treatises so this was a bit of an experience. By the end I felt he had some interesting points to make about things that are so big – like climate change – that they can’t be easily encompassed or conceived, but he did make this point several times in most chapters.

Nine Fox Gambit – Yoon Ha Lee

Chinese SF where calendars are weapons, and the weapons are weird.

The Massacre of Mankind – Stephen Baxter

A sequel to the War of the Worlds. Baxter enjoys destroying Metroland a bit too much.

Coffin Road – Peter May

Interesting thriller set on Harris. Very atmospheric.

Binary Storm – Christopher Hinz

Prequel to the excellent Liege Killer (and its less good sequels) written long after the original. Happily much more like the original than the sequels.


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`Pass-the-Harasser’ … to Turku

Disgraceful action by Turku University in hiring sexual harasser Christian Ott.

In the Dark

I noticed yesterday evening that there has recently been a substantial increase in the number of people viewing my posts about Christian Ott, the former Caltech Professor who eventually left his job there after harassing two female students there.

It wasn’t difficult to find out why there had been an upsurge in interest: Christian Ott has got a new job, at the University of Turku, in Finland. As far as I understand the situation – and please correct me if I’m wrong – he was `head-hunted’ for this position, so his appointment was not the result of an open competition and it seems the position was specifically created just for him.

UPDATE: the post was advertised here, but the gap between the deadline for applications – 10th December 2017 – and the appointment being announced is too short to be consistent with the usual processes of academic…

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Crunch time for Dark Matter?

Might as well throw this open to more people…

In the Dark

Gratuitous picture of the cluster Abel 2218, showing numerous gravitational lensing arcs

I was reading through an article by Philip Ball in the Grauniad this morning about likely breakthroughs in science for the forthcoming year. One of the topics discussed therein was dark matter. Here’s an excerpt:

It’s been agreed for decades that the universe must contain large amounts of so-called dark matter – about five times as much as all the matter visible as stars, galaxies and dust. This dark matter appears to exert a gravitational tug while not interacting significantly with ordinary matter or light in other ways. But no one has any idea what it consists of. Experiments have been trying to detect it for years, but all have drawn a blank. The situation is becoming grave enough for some researchers to start taking more seriously suggestions that what looks like dark matter is in fact…

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