Impact of redshift distribution uncertainties on Lyman-break galaxy cosmological parameter inference
Impact of redshift distribution uncertainties on Lyman-break galaxy cosmological parameter inference
Thu 12 Jun 16:00: Magnetic fields of neutron stars: simulations and observations
Neutron stars are the largest and the strongest magnets in the Universe. Their typical radius is around 10 km and their magnetic fields could reach values of 1e15 G. Structurally, the outer 1 km shell of a neutron star is its solid crust, while the inner part is its core. Magnetic fields shape observational properties of isolated and accreting neutron stars. Strong magnetic fields play the crucial role in explaining transient and persistent X-ray emission from Anomalous X-ray Pulsars and Soft Gamma Repeaters jointly known as magnetars. Magnetic fields are not constant and expected to evolve over time. In the last years, a significant progress was made in modelling magneto-thermal evolution of neutron star crust. Ohmic decay and Hall evolution explains multiple magnetar properties. In this colloquium, I summarise the main observational constrains currently available on magnetic fields of neutron stars and confront them with state-of-art numerical simulations. I will explain how current and future observations help us to learn more about magnetic field evolution and its structure. I also explain how the neutron star core can be modelled and show preliminary results for field evolution in the core.
- Speaker: Andrei Igoshev, Newcastle University
- Thursday 12 June 2025, 16:00-17:00
- Venue: Hoyle Lecture Theatre, Institute of Astronomy.
- Series: Institute of Astronomy Colloquia; organiser: Mor Rozner.
Thu 12 Jun 16:00: Magnetic fields of neutron stars: simulations and observations
Neutron stars are the largest and the strongest magnets in the Universe. Their typical radius is around 10 km and their magnetic fields could reach values of 1e15 G. Structurally, the outer 1 km shell of a neutron star is its solid crust, while the inner part is its core. Magnetic fields shape observational properties of isolated and accreting neutron stars. Strong magnetic fields play the crucial role in explaining transient and persistent X-ray emission from Anomalous X-ray Pulsars and Soft Gamma Repeaters jointly known as magnetars. Magnetic fields are not constant and expected to evolve over time. In the last years, a significant progress was made in modelling magneto-thermal evolution of neutron star crust. Ohmic decay and Hall evolution explains multiple magnetar properties. In this colloquium, I summarise the main observational constrains currently available on magnetic fields of neutron stars and confront them with state-of-art numerical simulations. I will explain how current and future observations help us to learn more about magnetic field evolution and its structure. I also explain how the neutron star core can be modelled and show preliminary results for field evolution in the core.
- Speaker: Andrei Igoshev, Newcastle University
- Thursday 12 June 2025, 16:00-17:00
- Venue: Hoyle Lecture Theatre, Institute of Astronomy.
- Series: Institute of Astronomy Colloquia; organiser: Mor Rozner.
NASA’s Chandra Sees Surprisingly Strong Black Hole Jet at Cosmic “Noon”
A black hole has blasted out a surprisingly powerful jet in the distant universe, according to a new study from NASA’s Chandra X-ray Observatory and discussed in our latest press release. This jet exists early enough in the cosmos that it is being illuminated by the leftover glow from the big bang itself.
Astronomers used Chandra and the Karl G. Jansky Very Large Array (VLA) to study this black hole and its jet at a period they call “cosmic noon,” which occurred about three billion years after the universe began. During this time most galaxies and supermassive black holes were growing faster than at any other time during the history of the universe.
The main graphic is an artist’s illustration showing material in a disk that is falling towards a supermassive black hole. A jet is blasting away from the black hole towards the upper right, as Chandra detected in the new study. The black hole is located 11.6 billion light-years from Earth when the cosmic microwave background (CMB), the leftover glow from the big bang, was much denser than it is now. As the electrons in the jets fly away from the black hole, they move through the sea of CMB radiation and collide with microwave photons. These collisions boost the energy of the photons up into the X-ray band (purple and white), allowing them to be detected by Chandra even at this great distance, which is shown in the inset.
Researchers, in fact, identified and then confirmed the existence of two different black holes with jets over 300,000 light-years long. The two black holes are 11.6 billion and 11.7 billion light-years away from Earth, respectively. Particles in one jet are moving at between 95% and 99% of the speed of light (called J1405+0415) and in the other at between 92% and 98% of the speed of light (J1610+1811). The jet from J1610+1811 is remarkably powerful, carrying roughly half as much energy as the intense light from hot gas orbiting the black hole.
The team was able to detect these jets despite their great distances and small separation from the bright, growing supermassive black holes — known as “quasars” — because of Chandra’s sharp X-ray vision, and because the CMB was much denser then than it is now, enhancing the energy boost described above.
When quasar jets approach the speed of light, Einstein’s theory of special relativity creates a dramatic brightening effect. Jets aimed toward Earth appear much brighter than those pointed away. The same brightness astronomers observe can come from vastly different combinations of speed and viewing angle. A jet racing at near-light speed but angled away from us can appear just as bright as a slower jet pointed directly at Earth.
The researchers developed a novel statistical method that finally cracked this challenge of separating effects of speed and of viewing angle. Their approach recognizes a fundamental bias: astronomers are more likely to discover jets pointed toward Earth simply because relativistic effects make them appear brightest. They incorporated this bias using a modified probability distribution, which accounts for how jets oriented at different angles are detected in surveys.
Their method works by first using the physics of how jet particles scatter the CMB to determine the relationship between jet speed and viewing angle. Then, instead of assuming all angles are equally likely, they apply the relativistic selection effect: jets beamed toward us (smaller angles) are overrepresented in our catalogs. By running ten thousand simulations that match this biased distribution to their physical model, they could finally determine the most probable viewing angles: about 9 degrees for J1405+0415 and 11 degrees for J1610+1811.
These results were presented by Jaya Maithil (Center for Astrophysics | Harvard & Smithsonian) at the 246th meeting of the American Astronomical Society in Anchorage, AK, and are also being published in The Astrophysical Journal. A preprint is available here. NASA’s Marshall Space Flight Center in Huntsville, Alabama, manages the Chandra program. The Smithsonian Astrophysical Observatory’s Chandra X-ray Center controls science operations from Cambridge, Massachusetts, and flight operations from Burlington, Massachusetts.
Read more from NASA’s Chandra X-ray ObservatoryLearn more about the Chandra X-ray Observatory and its mission here:
Visual Description
This release is supported by an artist’s illustration of a jet blasting away from a supermassive black hole.
The black hole sits near the center of the illustration. It resembles a black marble with a fine yellow outline. Surrounding the black hole is a swirling disk, resembling a dinner plate tilted to face our upper right. This disk comprises concentric rings of fiery swirls, dark orange near the outer edge, and bright yellow near the core.
Shooting out of the black hole are two streaky beams of silver and pale violet. One bright beam shoots up toward our upper right, and a second somewhat dimmer beam shoots in the opposite direction, down toward our lower left. These beams are encircled by long, fine, corkscrewing lines that resemble stretched springs.
This black hole is located 11.6 billion light-years from Earth, much earlier in the history of the universe. Near this black hole, the leftover glow from the big bang, known as the cosmic microwave background or CMB, is much denser than it is now. As the electrons in the jets blast away from the black hole, they move through the sea of CMB radiation. The electrons boost the energies of the CMB light into the X-ray band, allowing the jets to be detected by Chandra, even at this great distance.
Inset at our upper righthand corner is an X-ray image depicting this interaction. Here, a bright white circle is ringed with a band of glowing purple energy. The jet is the faint purple line shooting off that ring, aimed toward our upper right, with a blob of purple energy at its tip.
News Media ContactMegan Watzke
Chandra X-ray Center
Cambridge, Mass.
617-496-7998
mwatzke@cfa.harvard.edu
Lane Figueroa
Marshall Space Flight Center, Huntsville, Alabama
256-544-0034
lane.e.figueroa@nasa.gov
Starlink satellites are leaking radio signals that may ruin astronomy
Thu 12 Jun 10:00: Harnessing the power of multi-tracer intensity mapping to study early galaxy formation
Intensity mapping is a powerful technique for mapping the Universe using a variety of tracers, including both spectral lines and continuum emission. It serves as a highly complementary approach to traditional galaxy surveys, especially at high redshift where detecting individual galaxies becomes increasingly expensive and challenging. In this talk, I will provide a brief overview of my past and ongoing efforts to explore how multi-tracer intensity mapping can be leveraged to reveal the physics of early galaxy formation and its large-scale impact.
- Speaker: Guochao Sun, Northwestern University (Remote)
- Thursday 12 June 2025, 10:00-11:00
- Venue: Martin Ryle Meeting Room, KICC + Online.
- Series: 21cm Discussion Group; organiser: Harry Bevins.
Thu 12 Jun 14:00: The enigmatic long-period radio transients
The long-period radio transients are a newly-discovered class of Galactic radio sources that produce pulsed emission lasting tens of seconds to several minutes, repeating on timescales of tens of minutes to hours. Such cadence is unprecedented, and there is currently no clear emission mechanism or progenitor that can explain the observations, which include complex polarisation behaviour, pulse microstructure, and activity windows that range from hours to decades.
Could they be ultra-long period magnetars, and connected to the phenomenon of Fast Radio Bursts? Could they be white dwarf pulsars, defying the expectations of the magnetic field evolution of these stellar remnants? In this talk I will describe the ten discoveries made so far, informative simulations of their evolution, the potential physical explanations, and the prospects for detecting more of these sources in ongoing and upcoming radio surveys, that will help uncover their true nature.
- Speaker: Prof. Natasha Hurley-Walker (Curtin University)
- Thursday 12 June 2025, 14:00-15:00
- Venue: Coffee area, Battcock Centre.
- Series: Hills Coffee Talks; organiser: Charles Walker.
Mon 16 Jun 14:00: Free floating planets and their possible origins
In recent years, free floating planets, i.e. those planets not found to be in a planetary system and with no observable companions, have begun to be found in microlensing and direct imaging surveys. Observations have shown that they have a wide variety of masses, ranging from terrestrial-like to giant planets. Microlensing surveys predict that there could be on order tens of free floating planets per star in the Milky Way. How these planets form and arrive on their observed trajectories remains a very open and intriguing question.
Whilst there are many mechanisms for forming free floating planets, e.g. ejections from planet-planet interactions or gravitational collapse of gas within molecular clouds, very few models have predicted the properties of free floating planets on a global scale. In this talk I will present the outcomes of state-of-the-art circumbinary planet formation models, that naturally produce a large abundance free floating planets per system. I will show the resulting mass and velocity distributions arising from the models, which will then be extended to include stellar populations of both single and binary stars, taking into binary fractions, and separations. The population distributions show clear observable features that can be investigated by future missions such as Roman, where evidence of these features will directly point to the specific formation pathways of specific planets, as well as informing on the processes of the planet forming environment in which they originated.
- Speaker: Gavin Coleman [Queen Mary University London]
- Monday 16 June 2025, 14:00-15:00
- Venue: MR14 DAMTP and online.
- Series: DAMTP Astrophysics Seminars; organiser: Thomas Jannaud.
Mon 20 Oct 13:00: Title to be confirmed
Abstract not available
- Speaker: Enea Di Dio (University of Geneva)
- Monday 20 October 2025, 13:00-14:00
- Venue: CMS, Pav. B, CTC Common Room (B1.19) [Potter Room].
- Series: Cosmology Lunch; organiser: Louis Legrand.
Mon 17 Nov 13:00: Title to be confirmed
Abstract not available
- Speaker: Boryana Hadzhiyska (University of California, Berkeley)
- Monday 17 November 2025, 13:00-14:00
- Venue: CMS, Pav. B, CTC Common Room (B1.19) [Potter Room].
- Series: Cosmology Lunch; organiser: Louis Legrand.
Thu 12 Jun 11:15: The enigmatic long-period radio transients
The long-period radio transients are a newly-discovered class of Galactic radio sources that produce pulsed emission lasting tens of seconds to several minutes, repeating on timescales of tens of minutes to hours. Such cadence is unprecedented, and there is currently no clear emission mechanism or progenitor that can explain the observations, which include complex polarisation behaviour, pulse microstructure, and activity windows that range from hours to decades.
Could they be ultra-long period magnetars, and connected to the phenomenon of Fast Radio Bursts? Could they be white dwarf pulsars, defying the expectations of the magnetic field evolution of these stellar remnants? In this talk I will describe the ten discoveries made so far, informative simulations of their evolution, the potential physical explanations, and the prospects for detecting more of these sources in ongoing and upcoming radio surveys, that will help uncover their true nature.
- Speaker: Prof. Natasha Hurley-Walker (Curtin University)
- Thursday 12 June 2025, 11:15-12:00
- Venue: Martin Ryle Seminar Room, Kavli Institute.
- Series: Hills Coffee Talks; organiser: Charles Walker.
Wed 11 Jun 10:00: JWST Debris Disks: Transforming our Understanding of Exoplanetary Systems
Observations of debris disks provide unique insight into the environments in which planetary systems form and evolve. Debris disks are planetary systems containing planets, planetesimals, and dust. Collisions among these bodies produce observable secondary gas and dust which act as tracers for a host of processes with in the disk. JWST is revolutionizing our understanding of debris disks through exquisitely sensitive, high angular resolution near- to mid-infrared observations. I will present highlights from Cycle 1 programs including the discovery of (1) large, recent collisions in the archetypal beta Pic debris disk, (2) water ice in exo-Kuiper Belts, and (3) hot, florescent CO gas in young (
- Speaker: Christine Chen, STScI
- Wednesday 11 June 2025, 10:00-11:00
- Venue: Ryle seminar room + ONLINE - Details to be sent by email.
- Series: Exoplanet Seminars; organiser: Max Sommer.
Disk Evolution Study Through Imaging of Nearby Young Stars (DESTINYS): Evidence of planet-disk interaction in the 2MASSJ16120668-3010270 system
Disk Evolution Study Through Imaging of Nearby Young Stars (DESTINYS): Evidence of planet-disk interaction in the 2MASSJ16120668-3010270 system
A Reassessment of the Pantheon+ and DES 5YR Calibration Uncertainties: Dovekie
A Reassessment of the Pantheon+ and DES 5YR Calibration Uncertainties: Dovekie
Tue 10 Jun 16:00: 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.
Webb Sees Sombrero Galaxy in Near-Infrared
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
Searching for Ancient Rocks in the ‘Forlandet’ Flats
- Perseverance Home
- Science
- News and Features
- Multimedia
- Mars Missions
- Mars Home
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.
Share Details Last Updated Jun 06, 2025 Related Terms Explore More 3 min read Sols 4559-4560: Drill Campaign — Searching for a Boxwork Bedrock Drill SiteArticle
2 days ago 2 min read Sols 4556-4558: It’s All in a Day’s (box)Work
Article
3 days ago 2 min read Sols 4554–4555: Let’s Try That One Again…
Article
1 week ago Keep Exploring Discover More Topics From NASA Mars
All Mars Resources
Rover Basics
Mars Exploration: Science Goals