iiinova — where your digital self keeps evolving

Hossam Khalil @hossam.bsky.social · 19/08/2026

See the paper for the gas fraction at the virial radius (R200c) and for more interesting results. You can also read more about my research here: hossamkhalilastro.github.io/Research.html

hossamkhalilastro.github.io

Research – Hossam Khalil

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Hossam Khalil @hossam.bsky.social · 19/08/2026

We find that FLAMINGO's fiducial AGN feedback model provides the best match to our observed gas fraction-mass relation, with BAHAMAS and SIMBA also in good agreement. TNG100, EAGLE, and FABLE, however, overpredict the amount of hot gas retained in these systems.

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Hossam Khalil @hossam.bsky.social · 19/08/2026

We also constrain different implementations of active galactic nuclei (AGN) feedback models in cosmological hydrodynamical simulations and predict the suppression of the matter power spectrum due to baryonic physics on large scales.

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Hossam Khalil @hossam.bsky.social · 19/08/2026

Paper day! My second 1st-author paper has been accepted for publication in A&A and is now on the arXiv: arxiv.org/abs/2608.17735. We use X-ray data from the first eROSITA-DE all-sky survey (eRASS1) to study the hot gas (baryon) budget of nearby galaxy groups out to the virial radius🧵☄️

arxiv.org

eROSITA cosmology with galaxy groups: hot gas budget out to the virial radius

Non-gravitational processes that expel hot gas beyond the virial regions of groups and clusters of galaxies, known collectively as baryonic feedback, play a key role in reshaping the matter distributi...

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Hossam Khalil @hossam.bsky.social · 17/08/2025

Went to a dark-sky location for the Perseids last week. Ended up SATgazing a swarm of stupid starlinks.

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Hossam Khalil @hossam.bsky.social · 27/03/2025

Was a very nice talk. Love seeing X-ray spectral lines that clear for the first time!

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Reposted by Hossam Khalil

aaccomazzi.bsky.social @aaccomazzi.bsky.social · 11/02/2025

We are experiencing technical problems which are part of some growing pains (more content, more users, same infrastructure). At the moment there are no funding or programmatic threats to ADS. Thank you for your patience while we sort things out.

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Hossam Khalil @hossam.bsky.social · 14/04/2024

Here you can see AXES-2MRS groups (red ovals) overlaid with 2MRS individual galaxies (grey dots) and the local voids in our northern backyard. Refer to the paper for the southern hemisphere and many other interesting plots and results!

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Hossam Khalil @hossam.bsky.social · 14/04/2024

In Fig. 2, we show how AXES-2MRS traces the typical “honeycomb” structure of the local large-scale structure through X-ray detections!

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Hossam Khalil @hossam.bsky.social · 14/04/2024

AXES-2MRS allowed us to study the local dynamics (z < 0.065) of the Universe: we formed a smaller XMM-Newton subsample, for which we measured and constructed the scaling relations between different X-ray and optical observables, and tested the self-similar expectation.

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Hossam Khalil @hossam.bsky.social · 14/04/2024

Firstly, I must thank my supervisor Alexis Finoguenov for his unreserved support throughout this project. AXES-2MRS enhances the completeness of the galaxy cluster literature by adding many low-z low-luminosity low-mass systems that were previously missed.

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Hossam Khalil @hossam.bsky.social · 14/04/2024

My first first-author paper is out on the arXiv (arxiv.org/abs/2403.170...! A little over a year's work to release AXES-2MRS, an all-sky X-ray galaxy group catalogue based on extended X-ray sources from ROSAT and optical 2MRS galaxies. A thread🧵🔭.

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Hossam Khalil @hossam.bsky.social · 15/09/2023

It’s always relieving seeing such scuffed acronyms in top projects. I’m trying so hard to come up with one for a catalogue for my thesis work. Phew.

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Hossam Khalil @hossam.bsky.social · 15/09/2023

Just attended one of the nicest talks about NICER (Neutron star Composition explorER). Reminds me of the very first research project at ZC. Really nice to catch up with the pulsars.

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Hossam Khalil @hossam.bsky.social · 11/09/2023

Everyday I ask myself: why did I take an asteroid course this semester? But the answer remains shrouded in the mist

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Hossam Khalil @hossam.bsky.social · 09/09/2023

Yeah I think academic success statistically scales with the telescope diameter in the profile😂 Cool photo!

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Hossam Khalil @hossam.bsky.social · 09/09/2023

Nice note! I’m wondering how this new mass estimation would fit, on a larger scale, in the Local Group total mass estimate which is well-constrained by different methods.

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Hossam Khalil @hossam.bsky.social · 04/09/2023

Room temperature (arXiv) found baryons? Let’s see🔭🧪

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Hossam Khalil @hossam.bsky.social · 28/08/2023

Delayed for the nth time.. Truly cursed

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Hossam Khalil @hossam.bsky.social · 26/08/2023

Subfield feeds would be awesome!

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Hossam Khalil @hossam.bsky.social · 25/08/2023

Doing observational work is so satisfying. You don’t have to worry about right answers. You just get THE right answer.

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