Ian Harrison (@itrharrison) profile picture

Ian Harrison

@itrharrison

Workmanlike cosmologist.

 Cardiff
jb.man.ac.uk/~harrison/
Joined July 2009
  • Tweets4.7K
  • Following1.2K
  • Followers475
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Photo by Ian Harrison (@itrharrison)Photo by Ian Harrison (@itrharrison)Photo by Ian Harrison (@itrharrison)Photo by Ian Harrison (@itrharrison)Photo by Ian Harrison (@itrharrison)Photo by Ian Harrison (@itrharrison)Photo by Ian Harrison (@itrharrison)Photo by Ian Harrison (@itrharrison)Photo by Ian Harrison (@itrharrison)Photo by Ian Harrison (@itrharrison)
Warm greetings, astronomy fans and space enthusiasts! Here's what you've all been waiting for - Astronomy on Tap Cardiff! Four evenings of astronomy and space talks held in the City Center TOTALLY FREE! Secure your ticket here eventbrite.co.uk/e/astronomy… and read more below...
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The latest episode is out, in which @zemogle and @chrisenorth discuss supernovae, exoplanets and rovers. @itrharrison & @Dr_Whatson explain what we're learning by looking at the dawn of time. New podcast home - anchor.fm/pythag-astro (+ spotify.pythagastro.uk of course)
Pythagorean Astronomy • A podcast on Spotify for Creators

Pythagorean Astronomy • A podcast on Spotify for Creators

Astronomy news and interviews with scientists involved in the discoveries. Hosted by Dr Chris North (Cardiff University) and Dr Edward Gomez (Las Cumbres Observatory).

creators.spotify.com
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The SOC and LOC of the @RoyalAstroSoc UK National Astronomy Meeting 2023 (hosted at @cardiffuni @cardiffPHYSX) are happy to announce the call for session proposals is now live on the conference website nam2023.org! (1/3)
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UK cosmologists/astronomers interested in future opportunities with the @SimonsObs join us in September at the RAS for an SO UK community meeting! sites.google.com/view/souk-c…
SO:UK Community Meeting

SO:UK Community Meeting

6th to 8th September 2022 Royal Astronomical Society, London, United Kingdom

sites.google.com
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New paper day, attempting to answer the question - are any distant galaxies too big for our cosmological model? 🐘 arxiv.org/abs/2208.10479 In this study we use Extreme Value Statistics (EVS), a method for predicting the most massive object from a given distribution
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Replying to @agnes_cosmos @theDESurvey @jlynnmuir
Tests of gravity on cosmological scales 👇 Mainly purple (WL+RSD) versus red dashed (CMB+RSD).
2 sets of ellipses, several overlapping and others shifted.

ALT 2 sets of ellipses, several overlapping and others shifted.

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Exciting news 📢 I have a senior technician post available in my group. If you are interested in using iPSC neuron and microglia models to study neurodegeneration (and make lovely pictures like the one below) this is for you! krb-sjobs.brassring.com/TGne…📢 Please RT and share widely!
Image from Natalie Connor-Robson (@nlconnor_robson)
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One week left to apply for this. Go go go!
Erminia Calabrese (@ermcalabrese) profile pictureErminia Calabrese@ermcalabrese6 Jan 2022
Join us as a CMB cosmology research associate to work on @ACT_Pol , @SimonsObs and more at @cardiffPHYSX ! Apply via tinyurl.com/jobCardiffCMB by January 31st.
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We are now offering a series of limited walk-in sessions for COVID-19 booster vaccine doses. Check our website for more information including dates, times and locations: orlo.uk/JV23c #VaccinationSavesLives
Image from Cardiff and Vale University Health Board (@CV_UHB)
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Calling year 10 pupils from state schools who fancy messing around with @galaxyzoo data; sign up for our new program @OxfordPhysics: physics.ox.ac.uk/engage/scho… No experience required.
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Illustration: Jessie Muir @jlynnmuir Text: Ian Harrison @itrharrison Read about this new Hyperrank method applied to the DES Year 3 data here: arxiv.org/abs/2109.09636
Dark Energy Survey Year 3 results: Marginalisation over redshift...

Dark Energy Survey Year 3 results: Marginalisation over redshift...

Cosmological information from weak lensing surveys is maximised by dividing source galaxies into tomographic sub-samples for which the redshift distributions are estimated. Uncertainties on these...

arxiv.org
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Measurements of galaxy distance have uncertainty. This means our data are consistent with many possible variations of how galaxies are distributed. We use a method called Hyperrank to summarize those possibilities with just a few numbers. #DarkBites
Cartoon of a stick figure looking out at galaxies stacked in a histogram. In the background, many variations on that plot are sorted into categories.

ALT Cartoon of a stick figure looking out at galaxies stacked in a histogram. In the background, many variations on that plot are sorted into categories.

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Ian Harrison retweeted
NHS (@NHSuk) profile picture
NHS
@NHSuk20 Jul 2021
Get your second dose sooner. You can get your second dose after 8 weeks.

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Ian Harrison retweeted
Johanna (@johannateske) profile picture
Johanna@johannateske2 Jul 2021
Does your institution host a talk series suitable for grad students/postdocs in astronomy/astro-adjacent fields? Consider adding it to our growing repository, in time for this fall! Note you will need to request permission to edit, that's on purpose. 😁 tinyurl.com/ec-astro-talks
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Going from telescope images to catalogs of galaxy shapes and colors, to weak lensing measurements, to cosmology results is a complicated process. Along the way we do lots of tests to make sure our results are robust to uncertainties from each step of that analysis. #DarkBites
Cartoon of whimsical factory equipment, with different pieces of machinery representing shear analysis step.

ALT Cartoon of whimsical factory equipment, with different pieces of machinery representing shear analysis step.

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paraphrasing powerful Sarah White & @cosmicpudding's talks @Astro4Earth #EASLeiden2021: "Lets not go back to normal, it wasn't that great" -- everyone but comfortable western-passported white people w/o kids who hear well #TFoM
Image from Johannes Buchner (@JohannesBuchner)
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The results are IN!! We are proud to present our main results from our analysis of gravitational lensing and galaxy clustering using the first three years of DES observations. #DESY3 Here is a press release of our results, including a great 7-min video! news.fnal.gov/2021/05/dark-e…
Dark Energy Survey releases most precise look at the universe’s evolution

Dark Energy Survey releases most precise look at the universe’s evolution

The Dark Energy Survey collaboration has created the largest ever maps of the distribution and shapes of galaxies, tracing both ordinary and dark matter in the universe out to a distance of over 7...

news.fnal.gov
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We're almost there! Our big Year-3 cosmological analysis of gravitational lensing and galaxy clustering will be released THIS WEEK! 😮 As a refresher on what this analysis is all about, check out this Darchive article about our previous Year-1 analysis. darkenergysurvey.org/darchiv…
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Telegraph/STel literally confecting a moral panic a week: 25 April: bizarre misconstrual of speculative proposals at Sheffield (teapawt.net/AllyFogg/status/138659…) 9 May: different bizarre misconstrual of same Sheffield document (teapawt.net/JamesBSumner/status/13…) 14 May: same, but Oxford
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Ian Harrison retweeted
Alec Stapp (@AlecStapp) profile picture
Alec Stapp
@AlecStapp24 Apr 2021
Not The Onion: “EU proposing to regulate the use of Bayesian estimation”
Image from Alec Stapp (@AlecStapp)
Image from Alec Stapp (@AlecStapp)
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