Detailed theoretical modelling of the kinetic Sunyaev-Zel'dovich stacking power spectrum

Journal of Cosmology and Astroparticle Physics IOP Publishing 2026:01 (2026) 015

Authors:

Amy Wayland, David Alonso, Adrien La Posta

Abstract:

We examine, from first principles, the angular power spectrum between the kinematic Sunyaev-Zel'dovich effect (kSZ) and the reconstructed galaxy momentum — the basis of existing and future “kSZ stacking� analyses. We present a comprehensive evaluation of all terms contributing to this cross-correlation, including both the transverse and longitudinal modes of the density-weighted velocity field, as well as all irreducible correlators that contribute to the momentum power spectrum. This includes the dominant component, involving the convolution of the electron-galaxy and velocity-velocity power spectra, an additional disconnected cross-term, and a connected non-Gaussian trispectrum term. Using this framework, we examine the impact of other commonly neglected contributions, such as the two-halo component of the dominant term, and the impact of satellite galaxies. Finally, we assess the sensitivity of upcoming CMB experiments to these effects and determine that they will be sensitive to the cross-term, the connected non-Gaussian trispectrum term, the two-halo contribution and impact of satellite galaxies, at a significance level of ∼ 4-6σ. On the other hand, the contribution from longitudinal modes is negligible in all cases. These results identify the astrophysical observables that must be accurately modelled to obtain unbiased constraints on cosmology and astrophysics from near-future kSZ measurements.

Evidence of mutually exclusive outflow forms from a black hole X-ray binary

Nature Astronomy (2026) 1-9

Authors:

Zuobin Zhang, Jiachen Jiang, Francesco Carotenuto, Honghui Liu, Cosimo Bambi, Rob P Fender, Andrew J Young, Jakob van den Eijnden, Christopher S Reynolds, Andrew C Fabian, Julien N Girard, Joey Neilsen, James F Steiner, John A Tomsick, Stéphane Corbel, Andrew K Hughes

Abstract:

Accretion onto black holes often leads to the launch of outflows that substantially influence their surrounding environments. The two primary forms of these outflows are X-ray disk winds—hot, ionized gases ejected from the accretion disk—and relativistic jets, which are collimated streams of particles often expelled along the rotational axis of the black hole. While previous studies have revealed a general association between spectral states and different types of outflow, the physical mechanisms governing wind and jet formation remain debated. Here, using coordinated NICER and MeerKAT observations of the recurrent black hole X-ray binary 4U 1630–472, we identify a clear anti-correlation between X-ray disk winds and jets: during three recent outbursts, only one type of outflow is detected at a time. Notably, this apparent exclusivity occurs even as the overall accretion luminosity remains within the range expected for a standard thin disk, characteristic of the canonical soft state. These results suggest a competition between outflow channels that may depend on how the accretion energy is partitioned between the disk and the corona. Our findings provide observational constraints on jet and wind formation in X-ray binaries and offer a fresh perspective on the interplay between different modes of accretion-driven feedback.

ATLAS100 data release 1

University of Oxford (2026)

Authors:

Shubham Srivastav, Stephen Smartt

Abstract:

Public data release accompanying the ATLAS100 sample definition paper by Srivastav et al. (2026). The data release includes the cleaned and binned ATLAS light curves of 1729 transients in the sample. Also included is a catalog csv file with additional useful metadata for the transients in the sample, including host galaxy associations, any updated classifications, etc.

Framework for Neuro-Inclusive Digital Citizen Science: Results From the Neuro(Minorities)Science Collaboration

Citizen Science Theory and Practice Ubiquity Press 11:1 (2026) 29

Authors:

Alisa Apreleva, Heraldo Henrique Felix de Moraes, Frank Helk, Clémence Kress, Iain Thomson, Iain Harrison, Beverley Newing, Abraham Mateos Gallego, Gregory Flothe, Cheryl A Torres, Rhys Archer, Alice M Hawthorne Allen, Chris Hinman, Julian Collis, Ken Lyman, Andrey CRB Gorokhov, Rosemary F Johnson, Melanie Luise Knott, Michael Cuff, Mara Kerstin Johannes, Raphael Garti, Mayahuel Torres-Guerrero, Melanie Rosa, Seif Sekalala, Samantha Blickhan, Laura Trouille, Chris Lintott

Abstract:

Digital citizen science (DCS) operates as a socio-technical mode of public participation in research. While many DCS participants self-identify as neurodivergent, their perspectives have rarely been treated as a distinct design lens. Drawing on a large-scale 2024 survey of Zooniverse volunteers and a 2025 participatory international collaboration with 89 adult neurodivergent citizen scientists and allies contributing across multiple DCS platforms, this study develops an actionable framework of accessibility guidelines for neuro-inclusive DCS. Thematic text analysis of two qualitative datasets (84 working-group contributions and 1,669 de-identified 2024 survey responses) identified recurring accessibility barriers and organised 91 recommended features into 11 functional domains spanning participation from onboarding and task engagement to interface customisation, moderation, safety, and outreach. The framework positions neuro-inclusive accessibility as a methodological component shaping participation, retention, and research practice. Grounded in neurodivergent lived experience, the guidelines create pathways for more flexible participation across diverse DCS contexts.

A Young Supernova Selection Pipeline For The LSST Era

Monthly Notices of the Royal Astronomical Society Oxford University Press (OUP) (2025) staf2278

Authors:

Harry Addison, Chris Frohmaier, Kate Maguire, Robert C Nichol, Isobel Hook, Stephen J Smartt

Abstract:

Abstract Early-time spectroscopy of supernovae (SNe), acquired within days of explosion, yields crucial insights into their outermost ejecta layers, facilitating the study of their environments, progenitor systems, and explosion mechanisms. Recent efforts in early discovery and follow-up of SNe have shown the potential insights that can be gained from early-time spectra. Surveys such as the Time-Domain Extragalactic Survey (TiDES), conducted with the 4-meter Multi-Object Spectroscopic Telescope (4MOST), will provide spectroscopic follow-up of transients discovered by the Legacy Survey of Space and Time (LSST). Current simulations indicate that early-time spectroscopic studies conducted with TiDES data will be limited by the current SN selection criteria. To enhance early-time SN spectroscopic studies from TiDES-like surveys, we propose a set of selection criteria focusing on young SNe (YSNe), which we define as SNe prior to −10 days before peak brightness. Utilising the Zwicky Transient Facility transient alerts, we developed criteria to select YSNe while minimising the sample’s contamination rate to 23percnt. The developed criteria were applied to LSST simulations, yielding a sample of 694 Deep Drilling Field survey SNe and 56260 Wide Fast Deep survey SNe for follow-up. We demonstrate that our criteria enables the selection of SNe at early-times, enhancing future early-time spectroscopic SN studies from TiDES-like surveys. Finally, we investigated 4MOST-like observing strategies to increase the sample of spectroscopically observed YSNe. We propose that a 4MOST-like observing strategy that follows LSST with a delay of 3 days is optimal for a TiDES-like SN survey in terms of the number of classifiable spectra obtained, while a 1 day delay is most optimal for enhancing the early-time science in conjunction with our YSN selection criteria.