Tootfinder

Physical Properties of 6.7 Million Galaxies from the DESI Bright Galaxy Survey: Spectral Fitting and Systematic Tests with Mock Spectra
Niu Li, Hu Zou, Jinfu Gou, Weijian Guo, Wenxiong L, Haoming Song, Jipeng Sui, Xi Tan, Yunao Xiao, Jingyi Zhang
https://arxiv.org/abs/2607.19162 https://arxiv.org/pdf/2607.19162 https://arxiv.org/html/2607.19162
arXiv:2607.19162v1 Announce Type: new
Abstract: We present a comprehensive analysis of the physical properties of galaxies in the Dark Energy Spectroscopic Instrument (DESI) Data Release 1 (DR1) Bright Galaxy Survey (BGS), based on full spectral fitting of $\sim 6.7$ million galaxy spectra. Using a customized spectral fitting pipeline, we derive key physical parameters including stellar mass, stellar velocity dispersion, stellar population age, dust attenuation, and emission-line properties. To quantify the reliability and systematic uncertainties of our measurements, we construct a large set of mock spectra that closely reproduce the observed properties of DESI data, including realistic noise and spectral features. By comparing the recovered parameters with the known inputs, we assess the performance of the spectral fitting as a function of stellar continuum signal-to-noise ratio (S/N, defined as the ratio of the median continuum flux to its associated error) and redshift. We find that stellar masses can be robustly recovered with negligible bias for spectra with $\mathrm{S/N} \gtrsim 5$, while low-S/N spectra ($\mathrm{S/N} \lesssim 5$) show a mild systematic overestimation of $\sim 0.1$ dex and increased scatter. Similar trends are observed for stellar population parameters, while emission-line fluxes are recovered with high accuracy and minimal bias. We further validate our stellar mass estimates by comparison with independent measurements from photometric spectral energy distribution fitting, finding good overall consistency within the expected systematic uncertainties. The value-added catalog presented in this work enables a wide range of statistical studies of galaxy evolution with DESI, and provides a foundation for future analyses.
toXiv_bot_toot

We speak with moral philosopher Susan Neiman, author of the new book
"Call It Evil: Understanding the Trump Era".
Neiman argues that evil
— far from being an outdated religious concept
— is a vital way to understand how injustice works in the world.
The Trump administration’s abusive policies have been aided by a general reluctance to call them out as evil,
part of how people are “brainwashed … by the idea that morality is for losers, suckers, f…

“Call It Evil”: Philosopher Susan Neiman on Why Moral Clarity Matters in the Trump Era
We speak with moral philosopher Susan Neiman, author of the new book Call It Evil: Understanding the Trump Era. Neiman argues that evil — far from being an outdated religious concept — is a vital way to understand how injustice works in the world. The Trump administration’s abusive policies have been aided by a general reluctance to call them out as evil, part of how people are “brainwashed … by the idea that morality is for losers, suckers, fools,” she says. “People worry that it…

Big news! I just released version 0.9 of my 3d-printed #MorseCode single-paddle key system.
Changes:

• New grip that acts like a case. @…

Interested in airborne monitoring using computer vision? We (@…) just released annotated data with bounding boxes and species IDs for over 50,000 individual birds of 6 widely distributed species from our drone work in the Everglades.
https://doi.org/10.1002/ecy.70512

Vz-GAL Dusty Star-Forming Galaxies: Revisiting the CO-H2 Conversion Factor Tension
Prachi Prajapati, Axel Weiss, Dominik Riechers, Tom J. L. C. Bakx, Leindert A. Boogaard, Diana Ismail, Pierre Cox, Andrew J. Baker, Roberto Neri, Matthew Lehnert, Chentao Yang, Emilio Romano-Diaz, Hiddo S. B. Algera, Stefano Berta, Edoardo Borsato, Kirsty M. Butler, Asantha Cooray, Bethany Jones, Amelie Saintonge, Paul van der Werf
https://arxiv.org/abs/2607.18440 https://arxiv.org/pdf/2607.18440 https://arxiv.org/html/2607.18440
arXiv:2607.18440v1 Announce Type: new
Abstract: The CO luminosity-to-H$_2$ mass conversion factor ($\alpha_{CO}$) remains a debated uncertainty in determining molecular gas masses of high-redshift dusty star-forming galaxies (DSFGs). Dynamical mass constraints have often favored $\alpha_{CO}=0.8$~$M_{\odot}~{(K~km~{s}^{-1}~{pc}^{2})}^{-1}$, whereas dust- and radiative-transfer-based methods imply higher values. We revisit this ``tension" using the largest homogeneous sample of 21 unlensed $z\sim1-4$ DSFGs, with securely measured \coonezero luminosities from the VLA \vzgal survey and resolved ($\sim{0.1}^{\prime\prime}$) ALMA 1~mm dust continuum imaging. For 12 galaxies with robust modeling constraints, we derive molecular gas masses using dust spectral energy distribution modeling and the TUNER LVG framework, adopting a solar-metallicity gas-to-dust mass ratio of 100. Although not fully independent due to shared assumptions on dust properties, these approaches yield mutually consistent gas masses corresponding to $\alpha_{CO}\sim1.5-11.5$, with a median near the Galactic $\alpha_{CO}=4.3$. Isotropic virial dynamical masses agree with these gas masses when realistic molecular gas sizes are adopted, while our proposed ``mixed" (rotating, pressure-supported, thick-disk) estimator systematically underestimates dynamical masses, producing low $\alpha_{CO}$ limits. Using GN20 ($z=4.055$) as a case study, we show that resolved gas geometry and kinematics reconcile the discrepancy with LVG-derived $\alpha_{CO}$. Our results suggest that current data do not require $\alpha_{CO}=0.8$, and intermediate to near-Galactic values remain dynamically viable given uncertainties in gas geometry, dust properties, and gas-to-dust ratios. Further progress in calibrating $\alpha_{CO}$ in the early universe will require resolved molecular gas observations, physically motivated ISM modeling, and stringent constraints on dust properties.
toXiv_bot_toot

On Bluesky last night
Catherine Rampell noted that in documents Trump released
there were confirmations of Russia’s work on Trump’s behalf in 2020
and that China “did not intend to “try to affect the election.”
https://bsky.app/profile/crampell.bsky.social/…

Catherine Rampell (@crampell.bsky.social)
one of the supposedly damning docs the White House released tonight says Russia tried to undermine BIDEN. Also says China "prefers that President Trump be defeated" but actually "Beijing did not intend to try to affect the election" (!)

The Athletic's review of Dianna Russini's work concludes she was 'noncompliant' with standards https://www.nytimes.com/athletic/7562229/2026/09/03/dianna-russini-report-released-athletic-investigation/

An Athletic probe finds journalist Dianna Russini violated standards due to her relationship with an NFL coach but finds scant evidence it impacted coverage (Andrew Marchand/The Athletic)
https://www.nytimes.com/athletic/7562229/2026…

The Athletic’s review of Dianna Russini’s work concludes she was ‘noncompliant’ with standards
The NFL insider resigned in April after photos with her and New England Patriots head coach Mike Vrabel were published.

E3/DC (part of the Hager Group) has released a new bidirectional DC charger that can operate independently (a previous version could only be used with a complete home hybrid inverter setup).
It is compatible with 400V and 800V vehicles, works with VW ID. vehicles. Price unknown.

pv magazine spotlight für neue DC-Wallbox von E3/DC: Vom Carport zum Strommarkt - pv magazine Deutschland
Mit der bidirektionalen Wallbox "edsn" bringt E3/DC eine der ersten serienreifen Vehicle-to-Home-Lösungen auf den Markt. Gemeinsam mit Hauskraftwerk und Energiemanagement soll sie Elektrofahrzeuge als flexible Speicher in Gebäude, Strommarkt und Netz einbinden – und damit ein seit Jahren diskutiertes Konzept der Energiewende in die Praxis überführen.

My most recent work in #FreeCAD has been in models that I've been sharing with others, so I was using the released 1.1, and I finally felt like I didn't need to keep rebuilding the development version from source, as I have been doing most of the time for the past three years or so.
Now, watching this summary of new features coming in 1.2 26.3, I'm not sure I wa…