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DD
Dr. Deep Anand
@styrofoamplates.bsky.social
Senior Staff Scientist working on Hubble. views are my own.
200 followers133 following52 posts
Reposted by Dr. Deep Anand

excited to share ongoing results from the TRGB-SBF Project, where we aim to resolve the Hubble tension with a distance ladder which is independent of the usual Cepheid+Type Ia supernova route! 🔭🧪 arxiv.org/abs/2408.16810

arxiv paper and abstract:

The TRGB-SBF Project. II. Resolving the Virgo Cluster with JWST

Gagandeep S. Anand, R. Brent Tully, Yotam Cohen, Edward J. Shaya, Dmitry I. Makarov, Lidia N. Makarova, Maksim I. Chazov, John P. Blakeslee, Michele Cantiello, Joseph B. Jensen, Ehsan Kourkchi, Gabriella Raimondo

The Virgo Cluster is the nearest substantial cluster of galaxies to the Milky Way and a cornerstone of the extragalactic distance scale. Here, we present JWST/NIRCam observations that simultaneously cover the cores and halos of ten galaxies in and around the Virgo Cluster and are designed to perform simultaneous measurements of the tip of the red giant branch (TRGB) and surface brightness fluctuations (SBF). Seven of the targets are within the Virgo Cluster and where we are able to resolve some of the cluster's substructure, while an additional three provide important constraints on Virgo infall. The seven galaxies within Virgo itself all have SBF measurements from the Advanced Camera
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excited to share ongoing results from the TRGB-SBF Project, where we aim to resolve the Hubble tension with a distance ladder which is independent of the usual Cepheid+Type Ia supernova route! 🔭🧪 arxiv.org/abs/2408.16810

arxiv paper and abstract:

The TRGB-SBF Project. II. Resolving the Virgo Cluster with JWST

Gagandeep S. Anand, R. Brent Tully, Yotam Cohen, Edward J. Shaya, Dmitry I. Makarov, Lidia N. Makarova, Maksim I. Chazov, John P. Blakeslee, Michele Cantiello, Joseph B. Jensen, Ehsan Kourkchi, Gabriella Raimondo

The Virgo Cluster is the nearest substantial cluster of galaxies to the Milky Way and a cornerstone of the extragalactic distance scale. Here, we present JWST/NIRCam observations that simultaneously cover the cores and halos of ten galaxies in and around the Virgo Cluster and are designed to perform simultaneous measurements of the tip of the red giant branch (TRGB) and surface brightness fluctuations (SBF). Seven of the targets are within the Virgo Cluster and where we are able to resolve some of the cluster's substructure, while an additional three provide important constraints on Virgo infall. The seven galaxies within Virgo itself all have SBF measurements from the Advanced Camera
1
Reposted by Dr. Deep Anand

hey everyone, if you're interested in the Hubble Tension, *please* see this paper we just put out. 🔭 🧪 arxiv.org/abs/2408.11770

paper title and abstract:

JWST Validates HST Distance Measurements: Selection of Supernova Subsample Explains Differences in JWST Estimates of Local H0

Adam G. Riess, Dan Scolnic, Gagandeep S. Anand, Louise Breuval, Stefano Casertano, Lucas M. Macri, Siyang Li, Wenlong Yuan, Caroline D. Huang, Saurabh Jha, Yukei S. Murakami, Rachael Beaton, Dillon Brout, Tianrui Wu, Graeme E. Addison, Charles Bennett, Richard I. Anderson, Alexei V. Filippenko, Anthony Carr

JWST provides new opportunities to cross-check the HST Cepheid/SNeIa distance ladder, which yields the most precise local measure of H0. We analyze early JWST subsamples (~1/4 of the HST sample) from the SH0ES and CCHP groups, calibrated by a single anchor (N4258). We find HST Cepheid distances agree well (~1 sigma) with all 8 combinations of methods, samples, and telescopes: JWST Cepheids, TRGB, and JAGB by either group, plus HST TRGB and Miras. The comparisons explicitly include the measurement uncertainty of each method in N425
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hey everyone, if you're interested in the Hubble Tension, *please* see this paper we just put out. 🔭 🧪 arxiv.org/abs/2408.11770

paper title and abstract:

JWST Validates HST Distance Measurements: Selection of Supernova Subsample Explains Differences in JWST Estimates of Local H0

Adam G. Riess, Dan Scolnic, Gagandeep S. Anand, Louise Breuval, Stefano Casertano, Lucas M. Macri, Siyang Li, Wenlong Yuan, Caroline D. Huang, Saurabh Jha, Yukei S. Murakami, Rachael Beaton, Dillon Brout, Tianrui Wu, Graeme E. Addison, Charles Bennett, Richard I. Anderson, Alexei V. Filippenko, Anthony Carr

JWST provides new opportunities to cross-check the HST Cepheid/SNeIa distance ladder, which yields the most precise local measure of H0. We analyze early JWST subsamples (~1/4 of the HST sample) from the SH0ES and CCHP groups, calibrated by a single anchor (N4258). We find HST Cepheid distances agree well (~1 sigma) with all 8 combinations of methods, samples, and telescopes: JWST Cepheids, TRGB, and JAGB by either group, plus HST TRGB and Miras. The comparisons explicitly include the measurement uncertainty of each method in N425
1
Reposted by Dr. Deep Anand

for those interested in the Hubble tension and the new paper from the CCHP... here is an important thread copied over from Dan Scolnic on twitter. TLDR; the Hubble tension is alive and well. JWST and HST distance scales are in phenomenal agreement. new paper from SH0ES team with details soon. 🔭🧪

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for those interested in the Hubble tension and the new paper from the CCHP... here is an important thread copied over from Dan Scolnic on twitter. TLDR; the Hubble tension is alive and well. JWST and HST distance scales are in phenomenal agreement. new paper from SH0ES team with details soon. 🔭🧪

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Reposted by Dr. Deep Anand

hey all, please check out new paper led by JHU grad student Sean Li on JWST and the distance scale! in short, the JWST TRGB and HST (and JWST) Cepheid distance scales are in near-perfect agreement, and the Hubble tension absolutely persists. arxiv.org/abs/2408.00065 🔭🧪

RGB image of blue spiral galaxy NGC 3370 taken with JWST. a zoomed-in inset shows the (low) stellar density where the TRGB measurements for this paper are taken
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hey all, please check out new paper led by JHU grad student Sean Li on JWST and the distance scale! in short, the JWST TRGB and HST (and JWST) Cepheid distance scales are in near-perfect agreement, and the Hubble tension absolutely persists. arxiv.org/abs/2408.00065 🔭🧪

RGB image of blue spiral galaxy NGC 3370 taken with JWST. a zoomed-in inset shows the (low) stellar density where the TRGB measurements for this paper are taken
1
Reposted by Dr. Deep Anand
DDstyrofoamplates.bsky.social

“At the same time, the Chandra X-Ray Center and Space Telescope Science Institute, […], are planning for layoffs to reduce costs in line with NASA’s budget profile, moves that could involve dozens of people and which could take effect as soon as September.” 🥲 🔭🧪 spacenews.com/review-concl...

Review concludes proposed NASA budget cuts would end Chandra
Review concludes proposed NASA budget cuts would end Chandra

A NASA committee concluded there is no way to continue operating the Chandra X-ray Observatory with NASA’s proposed budget cuts in 2025.

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DDstyrofoamplates.bsky.social

“At the same time, the Chandra X-Ray Center and Space Telescope Science Institute, […], are planning for layoffs to reduce costs in line with NASA’s budget profile, moves that could involve dozens of people and which could take effect as soon as September.” 🥲 🔭🧪 spacenews.com/review-concl...

Review concludes proposed NASA budget cuts would end Chandra
Review concludes proposed NASA budget cuts would end Chandra

A NASA committee concluded there is no way to continue operating the Chandra X-ray Observatory with NASA’s proposed budget cuts in 2025.

0
DD
Dr. Deep Anand
@styrofoamplates.bsky.social
Senior Staff Scientist working on Hubble. views are my own.
200 followers133 following52 posts