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From Squiggles to Signals: Learning Useful Representations for Discovery in Time-Domain Astronomy

New large-scale astronomical surveys are observing orders of magnitude more sources than previous surveys, making standard approaches of visually identifying new and interesting phenomena unfeasible. Upcoming surveys such as the Vera Rubin Observatory’s Legacy Survey of Space and Time (LSST) and ongoing surveys such as the Transiting Exoplanet Survey Satellite (TESS) have the potential to revolutionize time-domain astronomy, providing opportunities to discover entirely new classes of events while also enabling a deeper understanding of known phenomena. The opportunity for serendipitous discovery in this domain is a new challenge that can be made systematic with data-driven methods, which are particularly suitable for identifying rare and unusual events in large datasets. In this talk, I’ll explore the potential for anomaly detection and representation learning in big datasets, and describe the challenge of applying these methods to real-time surveys. I’ll present novel machine learning methods for automatically detecting anomalous transient events such as kilonovae and peculiar supernovae, and characterising variable stars. I’ll explore the challenge of developing representative latent spaces useful for downstream machine learning tasks and present a novel causally-motivated foundation model. I’ll apply the approach to transients from the Zwicky Transient Facility (ZTF) and simulations of variable stars while discussing applications to upcoming surveys.

• Speaker: Daniel Muthukrishna (MIT)
• Tuesday 10 June 2025, 16:00-17:00
• Venue: Martin Ryle Seminar Room, KICC.
• Series: Astro Data Science Discussion Group; organiser: km723.

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NASA’s James Webb Space Telescope recently imaged the Sombrero Galaxy with its NIRCam (Near-Infrared Camera), which shows dust from the galaxy’s outer ring blocking stellar light from stars within the galaxy. In the central region of the galaxy, the roughly 2,000 globular clusters, or collections of hundreds of thousands of old stars held together by gravity, glow in the near-infrared. The Sombrero Galaxy is around 30 million light-years from Earth in the constellation Virgo. From Earth, we see this galaxy nearly “edge-on,” or from the side.NASA, ESA, CSA, STScI

After capturing an image of the iconic Sombrero galaxy at mid-infrared wavelengths in late 2024, NASA’s James Webb Space Telescope has now followed up with an observation in the near-infrared. In the newest image, released on June 3, 2025, the Sombrero galaxy’s tightly packed group of stars at the galaxy’s center is illuminated while the dust in the outer edges of the disk blocks some stellar light. Studying galaxies like the Sombrero at different wavelengths, including the near-infrared and mid-infrared with Webb, as well as the visible with NASA’s Hubble Space Telescope, helps astronomers understand how this complex system of stars, dust, and gas formed and evolved, along with the interplay of that material.

Learn more about the Sombrero galaxy and what this new view can tell us.

Image credit:  NASA, ESA, CSA, STScI

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2 min read

Searching for Ancient Rocks in the ‘Forlandet’ Flats NASA’s Mars Perseverance rover acquired this image of the “Fallbreen” workspace using its onboard Left Navigation Camera (Navcam). The camera is located high on the rover’s mast and aids in driving. This image was acquired on May 22, 2025 (Sol 1512, or Martian day 1,512 of the Mars 2020 mission) at the local mean solar time of 14:39:01. NASA/JPL-Caltech

Written by Henry Manelski, Ph.D. student at Purdue University

This week Perseverance continued its gradual descent into the relatively flat terrain outside of Jezero Crater. In this area, the science team expects to find rocks that could be among the oldest ever observed by the Perseverance rover — and perhaps any rover to have explored the surface of Mars — presenting a unique opportunity to understand Mars’ ancient past. Perseverance is now parked at “Fallbreen,” a light-toned bedrock exposure that the science team hopes to compare to the nearby olivine-bearing outcrop at “Copper Cove.” This could be a glimpse of the geologic unit rich in olivine and carbonate that stretches hundreds of kilometers to the west of Jezero Crater. Gaining insight into how these rocks formed could have profound implications for our constantly evolving knowledge of this region’s history. Perseverance’s recent traverses marked another notable transition. After rolling past Copper Cove, Perseverance entered the “Forlandet” quadrangle, a 1.2-square-kilometer (about 0.46 square mile, or 297-acre) area along the edge of the crater that the science team named after Forlandet National Park on the Norwegian archipelago of Svalbard. Discovered in the late 16th century by Dutch explorers, this icy set of islands captured the imagination of a generation of sailors searching for the Northwest Passage. While Perseverance is in the Forlandet quad, landforms and rock targets will be named informally after sites in and around this national park on Earth. As the rover navigates through its own narrow passes in the spirit of discovery, driving around sand dunes and breezing past buttes, we hope it channels the perseverance of the explorers who once gave these rocks their names.

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Efstathiou, Emeritus Professor of Astrophysics (1909) at Cambridge’s Institute of Astronomy, shares the prize with Professor John Richard Bond from the Canadian Institute for Theoretical Astrophysics and the University of Toronto.

They were recognised for their pioneering research in cosmology, in particular for their studies of fluctuations in the cosmic microwave background. Their predictions have been verified by an armada of ground-, balloon- and space-based instruments, leading to precise determinations of the age, geometry, and mass-energy content of the universe.

Cosmology has undergone a revolution in the past two decades, driven mainly by increasingly precise measurements of the angular power spectrum of fluctuations in the temperature and polarisation fields of the cosmic microwave background, a relic of the early universe, most notably by NASA’s Wilkinson Microwave Anisotropy Probe spacecraft (2001–2010) and the European Space Agency’s Planck spacecraft (2009–2013).

These fluctuations are small — the strength of the background radiation is the same in all directions to better than 0.01% and it is only slightly polarised — but they offer a glimpse of the universe when it was very young, a test of many aspects of fundamental physics, insights into the nature of dark matter and dark energy, and measurements of many fundamental cosmological parameters with accuracies unimaginable to cosmologists a few decades ago.

Although many researchers contributed to the development of the theoretical framework that governs the behaviour of the cosmic microwave background, Bond and Efstathiou emphasised the importance of the background as a cosmological probe and took the crucial step of making precise predictions for what can be learned from specific models of the history and the composition of the mass and energy in the universe.

Modern numerical codes used to interpret the experimental results are based almost entirely on the physics developed by Bond and Efstathiou. Their work exemplifies one of the rare cases in astrophysics where later experimental studies accurately confirmed unambiguous, powerful theoretical predictions.

The interpretation of these experiments through Bond and Efstathiou’s theoretical models shows that the spatial geometry of the observable universe is nearly flat, and yields the age of the universe with a precision of 0.15%, the rate of expansion of the universe with a precision of 0.5%, the fraction of the critical density arising from dark energy to better than 1%, and so on. The measurements also strongly constrain theories of the early universe that might have provided the initial “seed” for all the cosmic structure we see today, and the nature of the dark matter and dark energy that dominate the mass-energy content of the universe.

Both Bond and Efstathiou have worked closely with experimentalists to bring their predictions to the test: they have been heavily involved in the analysis of cosmic microwave background data arising from a wide variety of experiments of growing sophistication and accuracy.

George Efstathiou received his BA in Physics from the University of Oxford and PhD in Astronomy from Durham University. He has held postdoctoral fellowships at the University of California, Berkeley, USA and the University of Cambridge. He was Savilian Professor of Astrophysics at Oxford, where he served as Head of Astrophysics until 1994. He returned to Cambridge in 1997 as Professor of Astrophysics, where he also served as Director of the Institute of Astronomy and the first Director of the Kavli Institute for Cosmology. He received the 2022 Gold Medal of the Royal Astronomical Society. He is a Fellow of the Royal Society of London and the Royal Astronomical Society, UK. He is a Fellow of King’s College, Cambridge.

Originally published on the Shaw Prize website. 

Professor George Efstathiou has been awarded the Shaw Prize in Astronomy, one of the biggest prizes in the field.

Shaw PrizeJohn Richard Bond (left) and George Efstathiou (right)

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• Speaker: Madeleine McKenzie (Carnegie)
• Friday 20 June 2025, 11:30-12:30
• Venue: Ryle Seminar Room, KICC + online.
• Series: Galaxies Discussion Group; organiser: Sandro Tacchella.

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arXiv:2505.11224v2 Announce Type: replace Abstract: The discovery of hot Jupiters that orbit very close to their host stars has long challenged traditional models of planetary formation and migration. Characterising their atmospheric composition - mainly in the form of the carbon-to-oxygen (C/O) ratio and metallicity - can provide insights into their formation locations and evolution pathways. With JWST we can characterise the atmospheres of these types of planets more precisely than previously possible, primarily because it allows us to determine both their atmospheric oxygen and carbon composition. Here, we present a JWST NIRSpec/G395H transmission spectrum from 2.8-5.1$\mu m$ of WASP-94Ab, an inflated hot Jupiter with a retrograde misaligned orbit around its F-type host star. We find a relatively cloud-free atmosphere, with absorption features of H$_2$O and CO$_2$ at detection significances of $\sim 4\sigma$ and $\sim 11\sigma$, respectively. In addition, we detect tentative evidence of CO absorption at $\sim3\sigma$, as well as hints of sulphur with the detection of H$_2$S at a $\sim 2.5\sigma$ confidence level. Our favoured equilibrium chemistry model determines a C/O ratio of $0.49^{+0.08}_{-0.13}$ for WASP-94Ab's atmosphere, which is substellar compared to the star's C/O ratio of $0.68 \pm 0.10$. The retrieved atmospheric metallicity is similar to the star's metallicity as both are $\sim 2\times$ solar. We find that this sub-stellar C/O ratio and stellar metallicity can be best explained by pebble accretion or planetesimal accretion in combination with large-distance migration of the planet.

arXiv:2505.11224v2 Announce Type: replace Abstract: The discovery of hot Jupiters that orbit very close to their host stars has long challenged traditional models of planetary formation and migration. Characterising their atmospheric composition - mainly in the form of the carbon-to-oxygen (C/O) ratio and metallicity - can provide insights into their formation locations and evolution pathways. With JWST we can characterise the atmospheres of these types of planets more precisely than previously possible, primarily because it allows us to determine both their atmospheric oxygen and carbon composition. Here, we present a JWST NIRSpec/G395H transmission spectrum from 2.8-5.1$\mu m$ of WASP-94Ab, an inflated hot Jupiter with a retrograde misaligned orbit around its F-type host star. We find a relatively cloud-free atmosphere, with absorption features of H$_2$O and CO$_2$ at detection significances of $\sim 4\sigma$ and $\sim 11\sigma$, respectively. In addition, we detect tentative evidence of CO absorption at $\sim3\sigma$, as well as hints of sulphur with the detection of H$_2$S at a $\sim 2.5\sigma$ confidence level. Our favoured equilibrium chemistry model determines a C/O ratio of $0.49^{+0.08}_{-0.13}$ for WASP-94Ab's atmosphere, which is substellar compared to the star's C/O ratio of $0.68 \pm 0.10$. The retrieved atmospheric metallicity is similar to the star's metallicity as both are $\sim 2\times$ solar. We find that this sub-stellar C/O ratio and stellar metallicity can be best explained by pebble accretion or planetesimal accretion in combination with large-distance migration of the planet.

arXiv:2506.04337v1 Announce Type: new Abstract: We present flux measurements of the coronal lines [Fe VII] and [Fe X] spanning three decades, in the highly variable Active Galactic Nucleus (AGN) MKN 110. These coronal lines are sensitive to the spectral energy distribution (SED) of AGNs in the extreme ultraviolet (EUV). Neither [Fe VII] nor [Fe X] demonstrates variability in the short term on a weekly or monthly timescale. However, by taking advantage of a long term decrease in the continuum flux of MKN 110 on the order of years, we were able to track the [Fe VII] and [Fe X] fluxes as they respond to the continuum. We were able to detect a lag for [Fe VII] relative to the continuum at 5100 {\AA}, with a modal lag of 652 days, but were unable to detect a significant lag in the [Fe x] flux, though there exist significant uncertainties in the [Fe X] fit. These two lag results are not consistent and the line widths for the two line species also do not match. This provides strong evidence for stratification within the coronal line region (CLR). There is also evidence of a non-varying component within the coronal line flux, probably a result of a more extended region of origin. Taken together, these results suggest a CLR where the bulk of the [Fe VII] originates on parsec scales, but a portion of the [Fe VII] flux originates further out, at or beyond a 10 pc scale. These results also indicate the limitations of single-cloud models in describing the physical conditions of the CLR.

arXiv:2506.04337v1 Announce Type: new Abstract: We present flux measurements of the coronal lines [Fe VII] and [Fe X] spanning three decades, in the highly variable Active Galactic Nucleus (AGN) MKN 110. These coronal lines are sensitive to the spectral energy distribution (SED) of AGNs in the extreme ultraviolet (EUV). Neither [Fe VII] nor [Fe X] demonstrates variability in the short term on a weekly or monthly timescale. However, by taking advantage of a long term decrease in the continuum flux of MKN 110 on the order of years, we were able to track the [Fe VII] and [Fe X] fluxes as they respond to the continuum. We were able to detect a lag for [Fe VII] relative to the continuum at 5100 {\AA}, with a modal lag of 652 days, but were unable to detect a significant lag in the [Fe x] flux, though there exist significant uncertainties in the [Fe X] fit. These two lag results are not consistent and the line widths for the two line species also do not match. This provides strong evidence for stratification within the coronal line region (CLR). There is also evidence of a non-varying component within the coronal line flux, probably a result of a more extended region of origin. Taken together, these results suggest a CLR where the bulk of the [Fe VII] originates on parsec scales, but a portion of the [Fe VII] flux originates further out, at or beyond a 10 pc scale. These results also indicate the limitations of single-cloud models in describing the physical conditions of the CLR.

arXiv:2506.04309v1 Announce Type: new Abstract: Type Ia supernovae (SNe Ia) are standardisable candles: their peak magnitudes can be corrected for correlations between light curve properties and their luminosities to precisely estimate distances. Understanding SN Ia standardisation across wavelength improves methods for correcting SN Ia magnitudes. Using 150 SNe Ia from the Foundation Supernova Survey and Young Supernova Experiment, we present the first study focusing on SN Ia standardisation properties in the z band. Straddling the optical and near-infrared, SN Ia light in the z band is less sensitive to dust extinction and can be collected alongside the optical on CCDs. Pre-standardisation, SNe Ia exhibit less residual scatter in z-band peak magnitudes than in the g and r bands. SNe Ia peak z-band magnitudes still exhibit a significant dependence on light-curve shape. Post-standardisation, the z-band Hubble diagram has a total scatter of RMS = 0.195 mag. We infer a z-band mass step of $\gamma_{z} = -0.105 \pm 0.031$ mag, which is consistent within 1$\sigma$ of that estimated from gri data, assuming Rv = 2.61. When assuming different Rv values for high and low mass host galaxies, the z-band and optical mass steps remain consistent within 1$\sigma$. Based on current statistical precision, these results suggest dust reddening cannot fully explain the mass step. SNe Ia in the z band exhibit complementary standardisability properties to the optical that can improve distance estimates. Understanding these properties is important for the upcoming Vera Rubin Observatory and Nancy G. Roman Space Telescope, which will probe the rest-frame z band to redshifts 0.1 and 1.8.

arXiv:2506.04309v1 Announce Type: new Abstract: Type Ia supernovae (SNe Ia) are standardisable candles: their peak magnitudes can be corrected for correlations between light curve properties and their luminosities to precisely estimate distances. Understanding SN Ia standardisation across wavelength improves methods for correcting SN Ia magnitudes. Using 150 SNe Ia from the Foundation Supernova Survey and Young Supernova Experiment, we present the first study focusing on SN Ia standardisation properties in the z band. Straddling the optical and near-infrared, SN Ia light in the z band is less sensitive to dust extinction and can be collected alongside the optical on CCDs. Pre-standardisation, SNe Ia exhibit less residual scatter in z-band peak magnitudes than in the g and r bands. SNe Ia peak z-band magnitudes still exhibit a significant dependence on light-curve shape. Post-standardisation, the z-band Hubble diagram has a total scatter of RMS = 0.195 mag. We infer a z-band mass step of $\gamma_{z} = -0.105 \pm 0.031$ mag, which is consistent within 1$\sigma$ of that estimated from gri data, assuming Rv = 2.61. When assuming different Rv values for high and low mass host galaxies, the z-band and optical mass steps remain consistent within 1$\sigma$. Based on current statistical precision, these results suggest dust reddening cannot fully explain the mass step. SNe Ia in the z band exhibit complementary standardisability properties to the optical that can improve distance estimates. Understanding these properties is important for the upcoming Vera Rubin Observatory and Nancy G. Roman Space Telescope, which will probe the rest-frame z band to redshifts 0.1 and 1.8.

4 min read

Preparations for Next Moonwalk Simulations Underway (and Underwater)

What happens when the universe’s most magnetic object shines with the power of 1000 Suns in a matter of seconds? Thanks to NASA’s IXPE (Imaging X-ray Polarimetry Explorer), a mission in collaboration with ASI (Italian Space Agency), scientists are one step closer to understanding this extreme event. 

Magnetars are a type of young neutron star – a stellar remnant formed when a massive star reaches the end of its life and collapses in on itself, leaving behind a dense core roughly the mass of the Sun, but squashed down to the size of a city. Neutron stars display some of the most extreme physics in the observable universe and present unique opportunities to study conditions that would otherwise be impossible to replicate in a laboratory on Earth.

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Illustrated magnetar flyby sequence showing magnetic field lines. A magnetar is a type of isolated neutron star, the crushed, city-size remains of a star many times more massive than our Sun. Their magnetic fields can be 10 trillion times stronger than a refrigerator magnet's and up to a thousand times stronger than a typical neutron star's. This represents an enormous storehouse of energy that astronomers suspect powers magnetar outbursts.NASAs Goddard Space Flight Center/Chris Smith (USRA)

The magnetar 1E 1841-045, located in the remnants of a supernova (SNR Kes 73) nearly 28,000 light-years from Earth, was observed to be in a state of outburst by NASA’s Swift, Fermi, and NICER telescopes on August 21, 2024. 

A few times a year, the IXPE team approves requests to interrupt the telescope’s scheduled observations to instead focus on unique and unexpected celestial events. When magnetar 1E 1841-045 entered this brighter, active state, scientists decided to redirect IXPE to obtain the first-ever polarization measurements of a flaring magnetar.

Magnetars have magnetic fields several thousand times stronger than most neutron stars and host the strongest magnetic fields of any known object in the universe. Disturbances to their extreme magnetic fields can cause a magnetar to release up to a thousand times more X-ray energy than it normally would for several weeks. This enhanced state is called an outburst, but the mechanisms behind them are still not well understood. 

Through IXPE’s X-ray polarization measurements, scientists may be able to get closer to uncovering the mysteries of these events. Polarization carries information about the orientation and alignment of the emitted X-ray light waves; the higher the degree of polarization, the more the X-ray waves are traveling in sync, akin to a tightly choreographed dance performance. Examining the polarization characteristics of magnetars reveals clues about the energetic processes producing the observed photons as well as the direction and geometry of the magnetar magnetic fields. 

The IXPE results, aided by observations from NASA’s NuSTAR and NICER telescopes, show that the X-ray emissions from 1E 1841-045 become more polarized at higher energy levels while still maintaining the same direction of propagation. A significant contribution to this high polarization degree comes from the hard X-ray tail of 1E 1841-045, an energetic magnetospheric component dominating the highest photon energies observed by IXPE. “Hard X-rays” refer to X-rays with shorter wavelengths and higher energies than “soft X-rays.” Although prevalent in magnetars, the mechanics driving the production of these high energy X-ray photons are still largely unknown. Several theories have been proposed to explain this emission, but now the high polarization associated with these hard X-rays provide further clues into their origin.

This illustration depicts IXPE’s measurements of X-ray polarization emitting from magnetar 1E 1841-045 located within the Supernova Remnant Kes 73. At the time of observation, the magnetar was in a state of outburst and emitting the luminosity equivalent to 1000 suns. By studying the X-ray polarization of magnetars experiencing an outburst scientists may be able to get closer to uncovering the mysteries of these events. Michela Rigoselli/Italian National Institute of Astrophysics

The results are presented in two papers published in The Astrophysical Journal Letters, one led by Rachael Stewart, a PhD student at George Washington University, and the other by Michela Rigoselli of the Italian National Institute of Astrophysics..  

“This unique observation will help advance the existing models aiming to explain magnetar hard X-ray emission by requiring them to account for this very high level of synchronization we see among these hard X-ray photons,” said Stewart. “This really showcases the power of polarization measurements in constraining physics in the extreme environments of magnetars.”

Rigoselli, lead author of the companion paper, added, “It will be interesting to observe 1E 1841-045 once it has returned to its quiescent, baseline state to follow the evolution of its polarimetric properties.”

IXPE is a space observatory built to discover the secrets of some of the most extreme objects in the universe. Launched in December 2021 from NASA’s Kennedy Space Center on a Falcon 9 rocket, the IXPE mission is part of NASA’s Small Explorer series. 

IXPE, which continues to provide unprecedented data enabling groundbreaking discoveries about celestial objects across the universe, is a joint NASA and Italian Space Agency mission with partners and science collaborators in 12 countries. IXPE is led by NASA’s Marshall Space Flight Center in Huntsville, Alabama. BAE Systems, headquartered in Falls Church, Virginia, manages spacecraft operations together with the University of Colorado’s Laboratory for Atmospheric and Space Physics in Boulder.

Learn more about IXPE’s ongoing mission here:

https://www.nasa.gov/ixpe

Media Contact

Elizabeth Landau
NASA Headquarters
elizabeth.r.landau@nasa.gov
202-358-0845

Lane Figueroa
Marshall Space Flight Center, Huntsville, Ala.
lane.e.figueroa@nasa.gov
256.544.0034 

About the AuthorBeth Ridgeway

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Details Last Updated Jun 05, 2025 EditorBeth RidgewayContactLane FigueroaElizabeth R. Landauelizabeth.r.landau@nasa.govLocationMarshall Space Flight Center Related Terms

• IXPE (Imaging X-ray Polarimetry Explorer)
• Astrophysics
• Astrophysics Division
• Marshall Astrophysics
• Marshall Science Research & Projects
• Marshall Space Flight Center
• The Universe

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arXiv:2506.04229v1 Announce Type: new Abstract: We study the stellar distribution around supermassive black holes (SMBHs) in gas-rich nuclear star clusters (NSCs). NSCs could contain vast amounts of gas, which contribute significantly to shaping the stellar distribution, typically altering the stellar density cusp from the usual Bahcall \& Wolf 1976 solution and consequently affecting the dynamics in the NSC. The dense gaseous environment in NSCs gives rise to dynamical phenomena that are otherwise rare in other gas-free environments. Here we extend the derivation introduced in Bahcall \& Wolf 1976 to include an additional energy dissipation term associated with gas drag. We examine the effect of different forms of gas drag on the stellar density distribution. Finally, we discuss implications on the rates of tidal disruption events and other transients triggered by stellar interactions in gas-rich galactic nuclei.

arXiv:2506.04229v1 Announce Type: new Abstract: We study the stellar distribution around supermassive black holes (SMBHs) in gas-rich nuclear star clusters (NSCs). NSCs could contain vast amounts of gas, which contribute significantly to shaping the stellar distribution, typically altering the stellar density cusp from the usual Bahcall \& Wolf 1976 solution and consequently affecting the dynamics in the NSC. The dense gaseous environment in NSCs gives rise to dynamical phenomena that are otherwise rare in other gas-free environments. Here we extend the derivation introduced in Bahcall \& Wolf 1976 to include an additional energy dissipation term associated with gas drag. We examine the effect of different forms of gas drag on the stellar density distribution. Finally, we discuss implications on the rates of tidal disruption events and other transients triggered by stellar interactions in gas-rich galactic nuclei.

arXiv:2506.03245v1 Announce Type: new Abstract: Dwarf galaxies provide powerful laboratories for studying galaxy formation physics. Their early assembly, shallow gravitational potentials, and bursty, clustered star formation histories make them especially sensitive to the processes that regulate baryons through multi-phase outflows. Using high-resolution, cosmological zoom-in simulations of a dwarf galaxy from \textit{the Pandora suite}, we explore the impact of stellar radiation, magnetic fields, and cosmic ray feedback on star formation, outflows, and metal retention. We find that our purely hydrodynamical model without non-thermal physics - in which supernova feedback is boosted to reproduce realistic stellar mass assembly - drives violent, overly enriched outflows that suppress the metal content of the host galaxy. Including radiation reduces the clustering of star formation and weakens feedback. However, the additional incorporation of cosmic rays produces fast, mass-loaded, multi-phase outflows consisting of both ionized and neutral gas components, in better agreement with observations. These outflows, which entrain a denser, more temperate ISM, exhibit broad metallicity distributions while preserving metals within the galaxy. Furthermore, the star formation history becomes more bursty, in agreement with recent JWST findings. These results highlight the essential role of non-thermal physics in galaxy evolution and the need to incorporate it in future galaxy formation models.

arXiv:2506.03245v1 Announce Type: new Abstract: Dwarf galaxies provide powerful laboratories for studying galaxy formation physics. Their early assembly, shallow gravitational potentials, and bursty, clustered star formation histories make them especially sensitive to the processes that regulate baryons through multi-phase outflows. Using high-resolution, cosmological zoom-in simulations of a dwarf galaxy from \textit{the Pandora suite}, we explore the impact of stellar radiation, magnetic fields, and cosmic ray feedback on star formation, outflows, and metal retention. We find that our purely hydrodynamical model without non-thermal physics - in which supernova feedback is boosted to reproduce realistic stellar mass assembly - drives violent, overly enriched outflows that suppress the metal content of the host galaxy. Including radiation reduces the clustering of star formation and weakens feedback. However, the additional incorporation of cosmic rays produces fast, mass-loaded, multi-phase outflows consisting of both ionized and neutral gas components, in better agreement with observations. These outflows, which entrain a denser, more temperate ISM, exhibit broad metallicity distributions while preserving metals within the galaxy. Furthermore, the star formation history becomes more bursty, in agreement with recent JWST findings. These results highlight the essential role of non-thermal physics in galaxy evolution and the need to incorporate it in future galaxy formation models.