Archive for LSST

Weekly Update from the Open Journal of Astrophysics – 01/02/2025

Posted in OJAp Papers, Open Access, The Universe and Stuff with tags , , , , , , , , , , , , , , , , , , on February 1, 2025 by telescoper

It’s Saturday morning, so once again it’s time for an update of papers published at the Open Journal of Astrophysics. There were no papers to report last week but since the last update we have published four new papers, which brings the number in Volume 8 (2025) up to 11 and the total so far published by OJAp up to 246.

In chronological order of publication, the four papers published this week, with their overlays, are as follows. You can click on the images of the overlays to make them larger should you wish to do so.

First one up is  “A halo model approach for mock catalogs of time-variable strong gravitational lenses” by Katsuya T. Abe & Masamune Oguri (Chiba U, Japan), Simon Birrer & Narayan Khadka (Stony Brook, USA), Philip J. Marshall (Stanford, USA), Cameron Lemon (Stockholm U., Sweden), Anupreeta More (IUCAA, India), and the LSST Dark Energy Science Collaboration. It was published on 27th January 2025 in the folder marked Cosmology and NonGalactic Astrophysics. The paper discusses how to generate mock catalogs of strongly lensed QSOs and Supernovae on galaxy-, group-, and cluster-scales based on a halo model that incorporates dark matter halos, galaxies, and subhalos.

 

You can find the officially accepted version of this paper on arXiv here.

This paper, also published on Monday 27th January 2025, but in the folder Astrophysics of Galaxies, is “The Soltan argument at redshift 6: UV-luminous quasars contribute less than 10% to early black hole mass growth” by Knud Jahnke (MPI Heidelberg, Germany). This paper presents an argument that almost all growth of supermassive black hole mass at z>6 does not take place in UV-luminous quasars.

Here is a screen grab of the overlay, which includes the abstract:You can find the officially accepted version of the paper on the arXiv here.

The third paper to announce, published on 29th January 2025 in the folder Cosmology and NonGalactic Astrophysics, is “A Heavy Seed Black Hole Mass Function at High Redshift – Prospects for LISA” by Joe McCaffrey & John Regan (Maynooth U., Ireland), Britton Smith (Edinburgh U., UK), John Wise (Georgia Institute of Technology, USA), Brian O’Shea (Michigan State U., USA) and Michael Norman (University of California, San Diego). This is a numerical study of the growth rates of massive black holes in the early Universe and implications for their detection via gravitational wave emission.

You can see the overlay here:

 

The accepted version of this paper can be found on the arXiv here.

The last paper of this batch is “Forecasting the Detection of Lyman-alpha Forest Weak Lensing from the Dark Energy Spectroscopic Instrument and Other Future Surveys” by Patrick Shaw & Rupert A. C. Croft (Carnegie Mellon U., USA) and R. Benton Metcalf (U. Bologna, Italy). This paper, published on January 30th 2025, is about extending the applicationof  Lyman-α forest weak gravitational lensing to lower angular source densities than has previously been done, with forecasts for future spectral surveys. It is in the folder marked Cosmology and NonGalactic Astrophysics.

The overlay is here

 

You can find the accepted version on arXiv here.

Incidentally, we currently have 121 papers under review, including 81 under a revise and resubmit request.

That’s all for this week. I’ll do another update next Saturday.

Vera Rubin Observatory Update

Posted in The Universe and Stuff with tags , , on September 23, 2021 by telescoper

I couldn’t resist sharing this video showing the state of play with the Vera Rubin Observatory, currently under construction on Cerro Pachón in Chile. This is a huge survey telescope with an 8.4m mirror and enormous camera to match, the main task for which will be a ten-year Legacy Survey of Space and Time (LSST) which has the same initials as the former name of the telescope (the Large Synoptic Survey Telescope). That’s obviously so they carry on using the LSST name for their website and elsewhere.

Anyway, the mount assembly has now been installed and tested (in both altitude and azimuth) so you can now get good idea of what the telescope will look like when it’s completed. It’s an amazing piece of engineering, particularly when you see such a huge piece of kit so finely balanced that it can be moved by hand…

Assembly on the Mountain

Posted in The Universe and Stuff with tags , , , on March 9, 2021 by telescoper

Here’s a video showing the arrival and installation of the Top End Assembly (TEA) of the Simonyi Survey Telescope at the Vera C Rubin Observatory site on top of Cerro Pachón in Chile. The Vera C Rubin Observatory was previously known as the Large Synoptic Survey Telescope but was subsequently renamed in honour of the late Vera Rubin.

It’s fantastic to see this project progressing to this stage. I have been around long enough to remember when LSST, as it then was, seemed to be in the impossibly distant future (along with e.g. JWST). The fact that it is now really happening makes me feel extremely old! It’s still great to see though.

 

Everything we'd like to do with LSST data, but we don't know (yet) how [IMA]

Posted in The Universe and Stuff with tags , on December 16, 2016 by telescoper

Here’s a nice little summary paper (via arXiver) covering the data challenges posed by the Large Synoptic Survey Telescope (LSST) which will come online in 2020 or thereabouts.

To give a bit of a perspective, when the Sloan Digital Sky Survey (SDSS) began to collect astronomical data in 2000, it amassed more in its first few weeks than all data collected in the entire history of astronomy to that date.

Continuing at a rate of about 200 GB per night, SDSS has subsequently amassed more than 140 terabytes of information.

When LSST, which is in many ways a successor to SDSS, comes online it is expected to acquire that amount of data every five days…

arxiver's avatararXiver

http://arxiv.org/abs/1612.04772

The Large Synoptic Survey Telescope (LSST), the next-generation optical imaging survey sited at Cerro Pachon in Chile, will provide an unprecedented database of astronomical measurements. The LSST design, with an 8.4m (6.7m effective) primary mirror, a 9.6 sq. deg. field of view, and a 3.2 Gigapixel camera, will allow about 10,000 sq. deg. of sky to be covered twice per night, every three to four nights on average, with typical 5-sigma depth for point sources of $r$=24.5 (AB). With over 800 observations in $ugrizy$ bands over a 10-year period, these data will enable a deep stack reaching $r$=27.5 (about 5 magnitudes deeper than SDSS) and faint time-domain astronomy. The measured properties of newly discovered and known astrometric and photometric transients will be publicly reported within 60 sec after observation. The vast database of about 30 trillion observations of 40 billion objects will be mined for the unexpected and used…

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