Paper Day! You may have heard about these "Little Red Dots" in JWST data. Here we use new high quality spectra to show that the their spectral appearance is primarily determined by the properties of surrounding gas. LRDs are hot engines covered by dense gas arxiv.org/abs/2603.17667

One of the main conclusions so far is that a majority in the room thinks the powering engine in little red dots should be called quasars (and that the class of objects historically known as quasars could perhaps be called DABs; disk accreting black holes).

Paper day!! Little Red Dots (LRDs) are seen everywhere by JWST, but even after 3 years of relentless effort we are still debating what these things actually are. We decompose LRDs to show LRD - Host Galaxy = Black Hole Star (BH*)! 🧵 arxiv.org/abs/2601.20929 🔭 🧪

Vienna has a lively astronomy department - consider applying to the below if you'd be interested in a four year (!!) position here: 🔭☄️

Happy to share my introductory review article "JWST provides a new view of cosmic dawn: latest developments in studies of early galaxies" has now been published in Contemporary Physics! www.tandfonline.com/doi/full/10.... arxiv.org/abs/2511.04843

Time to spotlight the first paper of my PhD student Gauri Kotiwale that appeared on arXiv last week: Rapid, out of equilibrium metal enrichment indicated by a flat mass-metallicity relation at z ∼ 6 from NIRCam grism spectroscopy arxiv.org/abs/2510.19959

Delayed paper day! In work lead by my postdoc Claudia Di Cesare as part of the ALT survey, we provide a detailed census of the so-called star formation main sequence in the early Universe. arxiv.org/pdf/2510.19044

Where are you all now?

Delayed paper day! arxiv.org/abs/2510.00103 Led by Alberto Torralba, who is a postdoc in my group, we present the highest quality spectrum of a "Little Red Dot" yet known. This unveils new insights in the warm, dense layer of gas that is key to explain the most unusual spectral features of the LRDs!

Reviving Paper Threads: Paper day for my PhD student Ivan Kramarenko at @istaresearch.bsky.social ! "Hydrogen-Alpha as a Tracer of Star Formation in the SPHINX Cosmological Simulations" arxiv.org/abs/2509.05403 1/...

We found the most distant confirmed galaxy (some Sergej Boebka vibes 😅) arxiv.org/abs/2505.11263

More exciting measurements on the most luminous little red dot that I know of (F444W=22 at z=4.5!): an unambiguous AGN and a Balmer break in deep UNCOVER and ALT spectroscopy, led by Ivo Labbe arxiv.org/abs/2412.04557

Yesterday was paper day! With deep JWST data from the ALT survey we provide new independent evidence that the new population of faint AGNs in the early Universe seems to have so-called overly massive black holes compared to their stellar mass arxiv.org/abs/2412.02846

My institute ISTA in the nice Viennese forest in Austria now calls for PhD applications, deadline Jan 8 2024. Fully funded ~5 yr US style Grad School. Multiple positions in Astronomy are available. Please distribute and contact me for details! phd.pages.ist.ac.at

If you think MUSE is already oversubscribed, imagine that there will only be one ELT (instead of 4 UTs), which will have various instruments to commission when others can already observe. 😬

Hello Blue Sky! Very happy and grateful to be starting a research group in extragalactic astronomy and contribute to the development of astronomy at ISTA (ista.ac.at) as of this september!