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Posts by Nick Karnesis

Photograph of ESA Director of Science, Carole Mundell, and OHB System AG CEO, Chiara Pedersoli shaking hands at the signature event.

Photograph of ESA Director of Science, Carole Mundell, and OHB System AG CEO, Chiara Pedersoli shaking hands at the signature event.

LISA moves forward! 〰️

Today, at the #ParisAirShow, ESA and OHB System AG have sealed their agreement to build ESA's Laser Interferometer Space Antenna.

The triple-spacecraft mission will be the first space-based observatory to study gravitational waves 👉 www.esa.int/Science_Expl...

🔭 🧪 1/

10 months ago 136 27 3 4
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The LISA Science Team has just been completed! Two new members joined as Complementary Scientists for Space Weather and Multi-messenger astronomy 🧪🔭🌌
www.cosmos.esa.int/web/lisa/lis...
@lisacommunity.bsky.social

11 months ago 4 1 0 0
In the centre is an elliptical galaxy, seen as an oval-shaped glow around a small bright core. Around this is wrapped a broad band of light, appearing like a spiral galaxy stretched and warped into a ring, with bright blue lines drawn through it where the spiral arms have been stretched into circles. A few distant objects are visible around the ring on a black background.

In the centre is an elliptical galaxy, seen as an oval-shaped glow around a small bright core. Around this is wrapped a broad band of light, appearing like a spiral galaxy stretched and warped into a ring, with bright blue lines drawn through it where the spiral arms have been stretched into circles. A few distant objects are visible around the ring on a black background.

🆕 This new NASA/ESA/CSA James #Webb Space Telescope image shows a rare cosmic phenomenon called an 'Einstein ring' 🧪🔭

www.esa.int/ESA_Multimed... @science.esa.int @spacetelescope.bsky.social

1 year ago 612 94 16 10
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How to lie with data A comprehensive guide

Finally finished a small guide on -how to lie with data- ! Take a look:

karnesis.github.io/2023-09-05-h...

Or, in other words, how to protect ourselves from the chaos of information out there... 🧪🔭📈

1 year ago 1 0 0 0

Omg

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Money and murder: the dark side of the Asilomar meeting on recombinant DNA The famed 1975 conference about a controversial genetic technology is feted as an example of how scientific self-regulation works. But more significant is what wasn’t discussed.

An amazing piece by M. Cobb! Reads like a spy movie 🕵️
doi.org/10.1038/d415...

1 year ago 1 0 0 0

They found a way to litter from space

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A figure from the paper (Figure 4). It shows the locations of known hypervelocity stars as black circles, with the predicted overdensity that the LMC would cause shown in red. Full caption:

Predicted on-sky overdensity of hypervelocity stars originating from a 6 × 105M⊙ supermassive black hole in the
LMC. The black open circles denote the Galactic coordinates of hypervelocity stars detected in the HVS Survey, while the
grey-shaded regions mark areas excluded from the survey. The current position of the LMC is illustrated with a representative
image, and its orbital trajectory is drawn with a red arrow. The forward model incorporating an SMBH in the LMC along with
the selection effects of the HVS Survey predicts a prominent overdensity of HVS in the region enclosed by the red contours. The
overdensity arises because stars are boosted in the direction of the LMC’s orbit. This model accurately reproduces the observed
overdensity location, supporting the hypothesis of an SMBH in the LMC as a source of these stars.

A figure from the paper (Figure 4). It shows the locations of known hypervelocity stars as black circles, with the predicted overdensity that the LMC would cause shown in red. Full caption: Predicted on-sky overdensity of hypervelocity stars originating from a 6 × 105M⊙ supermassive black hole in the LMC. The black open circles denote the Galactic coordinates of hypervelocity stars detected in the HVS Survey, while the grey-shaded regions mark areas excluded from the survey. The current position of the LMC is illustrated with a representative image, and its orbital trajectory is drawn with a red arrow. The forward model incorporating an SMBH in the LMC along with the selection effects of the HVS Survey predicts a prominent overdensity of HVS in the region enclosed by the red contours. The overdensity arises because stars are boosted in the direction of the LMC’s orbit. This model accurately reproduces the observed overdensity location, supporting the hypothesis of an SMBH in the LMC as a source of these stars.

A very fascinating paper went up on the arXiv today!

Jesse Han & El-Badry et al. reanalysed the 21 known 'hypervelocity' stars in the #milkyway.

They find strong evidence that the LMC (Large Milky/Magellanic Cloud) has a supermassive black hole at its core! 🤯 arxiv.org/abs/2502.00102

1 year ago 296 80 5 16
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Gravitational radiation in black-hole collisions at the speed of light.
I. Perturbation treatment of the axisymmetric collision

P. D. D'Eath
Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Silver Street, Cambridge CB3 9EW, England

P. N. Payne
59, The Avenue, Nedlands 6009, Western Australia
(Received 4 February 1992)

Gravitational radiation in black-hole collisions at the speed of light. I. Perturbation treatment of the axisymmetric collision P. D. D'Eath Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Silver Street, Cambridge CB3 9EW, England P. N. Payne 59, The Avenue, Nedlands 6009, Western Australia (Received 4 February 1992)

My favorite serendipitous alignment of paper topic and author names occurred #OTD in 1992, when Dr. D'Eath and Dr. Payne submitted 3 papers to Physical Review exploring the physics of black holes smashing into each other at relativistic speeds.
🧪 ⚛️ ⚫️→💥←⚫️

journals.aps.org/prd/abstract...

1 year ago 46 10 3 2
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White House pauses all federal grants, sparking confusion The Trump administration has put a hold on all federal financial grants and loans, affecting tens of billions of dollars in payments.

I think some people hear “grants” and think that without them, scientists and government workers just have less stuff to play with at work. But grants fund salaries for students, academics, researchers, and people who work in all areas of public service.

“Pausing” grants means people don’t eat.

1 year ago 43420 14385 1582 944

I've always disliked the view that the value of a degree is in landing a job

Education is for life. A job is a small (but important) part of life

I would love to teach because you find the topic fascinating, rather than because your employer doesn't want to train you themselves

1 year ago 7 3 0 0

Today I was asked in an interview about folks who use the weirdness of ✨quantum✨ to hawk pseudoscience junk. I think that kind of grift proliferates because of a big misunderstanding a lot of folks have about quantum mechanics, which is not really their fault!
🧵

1 year ago 1761 349 48 38

Yey, the LISA Consortium is here!

1 year ago 1 0 0 0

Yep, took ages for me as well 😅

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OK- here we go. Sorry for the delay, I was not prepared for the exertion required in the thrill-a-minute adventure that is… CACAO FERMENTATION.

Yes, this will actually take 5 days. After that two days of drying. I’m not making this up. Nothing happens. Really. You’ll see.

Anyway, off we go!

1 year ago 2323 496 130 233
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A super nice video explaining the LISA mission! 🧪🔭

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By the way, this non-stationary component of stochastic GW signal is generated by the millions of Double White Dwarfs in our galaxy 🌌

Bottomline: we now have a neat way of detecting non-Gaussianities or non-stationarities. Hopefully a useful tool for the community! 🧵 5/5

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In our newest work we apply this idea to stochastic signals in the LISA data, and it works quite well! Take a look at this figure, where the ξ parameter of the hyperbolic (a ξ>0 indicates non-Gaussianities), clearly points to the part of the data where the astrophysical component dominates. 🧵 4/5

1 year ago 0 0 1 0
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Heavy-tailed likelihoods for robustness against data outliers: Applications to the analysis of gravitational wave data In recent years, the field of Gravitational Wave Astronomy has flourished. With the advent of more sophisticated ground-based detectors and space-based observatories, it is anticipated that Gravitatio...

This idea was first used in the context of Gravitational Waves Data Analysis by our brilliant student A. Sasli in this paper: arxiv.org/abs/2305.04709
Among others, she found that the only downside in using this likelihood instead of the usual Gaussian one, is the extra computational power. 🧵 3/5

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In this paper, we try to estimate the overall shape of the statistics of the residual data, using the hyperbolic likelihood. The hyperbolic likelihood is quite flexible, and can adjust its shape according to the distribution of the given data! 🧵 2/5

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Characterization of non-Gaussian stochastic signals with heavier-tailed likelihoods Future Gravitational Wave observatories will give us the opportunity to search for stochastic signals of astrophysical, or even cosmological origins. However, parameter estimation and search will be c...

Ok, lets put out my first post here about a new paper that we uploaded on the arXiv! 🧪 #astronomy #science #gws

The paper is about detecting departures from Gaussianities using a heavier-tailed likelihood. 🔕

Check it here: arxiv.org/abs/2410.14354

🧵 1/5

1 year ago 1 1 1 0

"cold, desolate, empty space" is a great name for a band 🔥

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A 23x79 pixel image that contains depictions of the numbers 1-10, the solar system, the general shape of humans, basic biochemical structures, and the Arecibo dish used to broadcast the message. It looks like graphics from an Atari 2600 game.

Image: NASA / JPL

A 23x79 pixel image that contains depictions of the numbers 1-10, the solar system, the general shape of humans, basic biochemical structures, and the Arecibo dish used to broadcast the message. It looks like graphics from an Atari 2600 game. Image: NASA / JPL

Hubble image of the globular cluster M13. It is a dense and glittering collection of white, pale blue, and golden yellow stars.

NASA, ESA, and the Hubble Heritage Team (STScI/AURA); Acknowledgment: C. Bailyn (Yale University), W. Lewin (Massachusetts Institute of Technology), A. Sarajedini (University of Florida), and W. van Altena (Yale University)

Hubble image of the globular cluster M13. It is a dense and glittering collection of white, pale blue, and golden yellow stars. NASA, ESA, and the Hubble Heritage Team (STScI/AURA); Acknowledgment: C. Bailyn (Yale University), W. Lewin (Massachusetts Institute of Technology), A. Sarajedini (University of Florida), and W. van Altena (Yale University)

The "Arecibo Message" was beamed towards globular cluster M13, in the constellation Hercules, #OTD in 1974. The broadcast took place during the dedication of an upgrade to the radio telescope.

It was the first message sent with the intention of alerting extraterrestrials to life on Earth. 🧪 🔭 👽

1 year ago 110 28 7 8
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Moon news 1: The first candidate #exomoon has been discovered by gravitational lensing. http://goo.gl/x4HVIV

12 years ago 7 1 1 0
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