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#cosmology

8 posts7 participants0 posts today
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Gravity Grinch

Another interesting strong lensing discovery by @NASAWebb : arxiv.org/abs/2504.03571
"if a bottom-heavy IMF for elliptical gals is employed, stellar mass estimations increase and can account for the majority of the lensing mass (up to ∼83\%), reducing the need for dark matter"!

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arXiv.orgJWSTs PEARLS: NIRCam imaging and NIRISS spectroscopy of a $z=3.6$ star-forming galaxy lensed into a near-Einstein Ring by a $z=1.258$ massive elliptical galaxyWe present the discovery, and initial lensing analysis, of a high-redshift galaxy-galaxy lensing system within the JWST-PEARLS/HST-TREASUREHUNT North Ecliptic Pole Time Domain Field (designated NEPJ172238.9+655143.1). The lensing geometry shears a $z=3.6\pm0.1$ star-forming galaxy into a near-Einstein ring with a radius of 0\farcs92, consisting of 4 primary images, around a foreground massive elliptical galaxy at $z=1.258\pm0.005$. The system is fortuitously located within the NIRISS F200W footprint of the PEARLS survey, enabling spectroscopic identification of the 8500A TiO band in the foreground galaxy and allowing tight constraints to be placed on the redshift of the background galaxy based on its continuum detection and lack of strong emission lines. We calculate magnification factors of $2.6<μ<8.4$ for the four images and a total lensing mass of $(4.08 \pm 0.07)\times10^{11}M_\odot$. SED fitting of the foreground elliptical galaxy within the Einstein radius reveals a stellar mass of $\sim1.26\times10^{11}M_\odot$, providing a mass/light ratio of 3.24. Employing simple scaling relations and assumptions, an NFW dark matter halo is found to provide the correct remaining mass within $0.12^{+0.21}_{-0.09}$dex. However, if a bottom-heavy IMF for elliptical galaxies is employed, stellar mass estimations increase and can account for the majority of the lensing mass (up to $\sim$83\%), reducing the need for dark matter. This system further demonstrates the new discovery space that the combined wavelength coverage, sensitivity and resolution of JWST now enables.
#DarkMatter#Cosmology#StrongGravitationalLensing
Public
UFO FEED

ufofeed.com/118907/nasa-disgus NASA Disgusted by Elon Musk’s Disrespect. Workers affected by the layoffs were only given 30 days’ notice — instead of 60, as spelled out in federal government guidance — and have even been denied time-off awards. #Astrobiology #Astrophysics #Cosmology #PlanetaryScience #Space #SpaceExploration

NASA Disgusted by Elon Musk's Disrespect. Workers affected by the layoffs were only given 30 days' notice — instead of 60, as spelled out in federal government guidance — and have even been denied time-off awards.
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Rowan Brad Quni

@Bibliothecaris what a delight to see this post and briefly look at the abstract. It seems I'm finally learning how to use Mastodon in finding work that aligns with my own research in Information Dynamics (formerly the Informational Universe hypothesis).

The nexus with this research is my own finding of a resolution parameter to unify seemingly disparate frameworks, from classical Newtonian #physics to EFE/general relativity; through quantum mechanics and beyond into metaphysical #cosmology.

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Suzanne Aldrich (she/her)

🎬 PS: For a beautifully clear (and delightfully mind-bending!) explanation of what might have existed before the Big Bang, check out PBS Space Time’s fantastic episode, "What Happened Before the Big Bang?" hosted by astrophysicist Matt O’Dowd. Highly recommended as a thoughtful companion to this thread! 🌌🌀✨

👉 Watch it here on PBS Space Time pbs.org/video/what-happened-be

www.pbs.orgPBS Space Time | What Happened Before the Big Bang? | Season 5 | Episode 29We actually have a pretty good idea of what might have happened before the Big Bang.
#PBS#SpaceTime#Cosmology
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Suzanne Aldrich (she/her)

📝 Important note:
These visuals are illustrative only—not precise physical depictions of magnitudes or forces involved. Actual conditions during inflation involved extreme energies (near ~10¹⁶ GeV), densities, and scales far beyond intuitive visualization. My illustrations aim purely for conceptual clarity.

Enjoy exploring our cosmic origins! ✨🔭🌠
#Cosmology #Inflation #BigBang #PrimordialBlackHoles #QuantumPhysics #Astrophysics

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Suzanne Aldrich (she/her)

🕳️ Clip 8: Transition to Primordial Universe (Black Holes Form)
This visualization illustrates tiny density fluctuations collapsing into primordial black holes (PBHs) within the hot early universe plasma—originally proposed by Hawking & Carr (1970s). PBHs could influence cosmic structure and potentially explain dark matter. Observational searches ongoing, including data from JWST, LIGO, and future space missions.
🎬 Watch the full-res Sora videos here! sora.com/g/gen_01jqmfmsabfbfsr
🔗 Primordial Black Holes (Carr, Hawking) arxiv.org/abs/2002.12778
🔭 Evidence: Ongoing searches via gravitational lensing (JWST), gravitational waves (LIGO), and large-scale surveys (DESI).
#Cosmology #Inflation #BigBang #PrimordialBlackHoles #QuantumPhysics #Astrophysics

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