Hubble Space Telescope | A Drop in the Light Bucket: How Do We Measure a Galaxy? @hubblespacetelescope | Uploaded May 2023 | Updated October 2024, 5 hours ago.
Amanda Pagul, Space Telescope Science Institute
Tracing back to the Hubble Deep Field in the 1990s, galaxy surveys with space telescopes have become a fundamental part of cosmological studies. Newer surveys have grown both larger and deeper to probe more galaxies at greater distance and detail. One such survey, Hubble’s Frontier Fields program, leverages gravitational lensing to push Hubble beyond even its impressive technical limits.
To extract understanding of how galaxies change across space and time, a crucial process is to convert these images into catalogs of galaxies with measured properties. Given the various observed wavelengths, cosmological redshift, galaxy development over billions of years, and numerous other factors, defining a reliable set of galaxy characteristics is a significant challenge. Dr. Pagul will describe previous survey results with galaxy cluster data from the Hubble Space Telescope and future work with the James Webb Space Telescope.
4:30 - News from the Universe
14:54 - Featured Speaker
1:07:54 - Live Q&A
Host: Frank Summers, , Space Telescope Science Institute
Recorded live on Tuesday, May 2, 2023
More information: www.stsci.edu/public-lectures
#STScI #galaxies #astronomy #space #telescopes #Hubble #NASAWebb #survey #galaxies #HubbleDeepField
Amanda Pagul, Space Telescope Science Institute
Tracing back to the Hubble Deep Field in the 1990s, galaxy surveys with space telescopes have become a fundamental part of cosmological studies. Newer surveys have grown both larger and deeper to probe more galaxies at greater distance and detail. One such survey, Hubble’s Frontier Fields program, leverages gravitational lensing to push Hubble beyond even its impressive technical limits.
To extract understanding of how galaxies change across space and time, a crucial process is to convert these images into catalogs of galaxies with measured properties. Given the various observed wavelengths, cosmological redshift, galaxy development over billions of years, and numerous other factors, defining a reliable set of galaxy characteristics is a significant challenge. Dr. Pagul will describe previous survey results with galaxy cluster data from the Hubble Space Telescope and future work with the James Webb Space Telescope.
4:30 - News from the Universe
14:54 - Featured Speaker
1:07:54 - Live Q&A
Host: Frank Summers, , Space Telescope Science Institute
Recorded live on Tuesday, May 2, 2023
More information: www.stsci.edu/public-lectures
#STScI #galaxies #astronomy #space #telescopes #Hubble #NASAWebb #survey #galaxies #HubbleDeepField
![Cosmic Reef: NGC 2014 & NGC 2020 [Ultra HD]](https://i.ytimg.com/vi/WoFQTYUSi_U/hqdefault.jpg "Cosmic Reef: NGC 2014 & NGC 2020 [Ultra HD]
This science visualization presents the dramatic landscape of two nebulas in the Large Magellanic Cloud. The video, based on images by NASAs Hubble Space Telescope, takes viewers on a close-up tour of the nebulas three-dimensional structures, as envisioned by scientists and artists.
The movie begins with the Hubble view of NGC 2014 (lower left) and NGC 2020 (upper right). The region has been nicknamed the Cosmic Reef, because of its resemblance to an undersea world. The camera then flies past myriad stars for a close-up look at NGC 2014. The first stop is the bubble of hot gas on the left that has a coral-like appearance. Energetic ultraviolet light from the systems most massive stars has heated the gas, while strong stellar winds (streams of charged particles) help create its bubble structure.
The journey continues into the heart of the nebula, home to extraordinarily massive and bright stars. The glowing gas in this region is bathed in the stars intense luminosity. In contrast, the dark, denser gas is resisting that radiation, and is blown back to form craggy, mountainous shapes. The virtual flight moves past ridges, valleys, and pockets of new star formation.
The camera then rises up and over a ridge of NGC 2014, revealing the three-dimensional structure of neighboring NGC 2020. The Wolf-Rayet star at its core is the mammoth, intensely hot source of this nebula. Episodes of outbursts from the young star have produced cloudy rings and clumps in the bright blue gas. While Hubble views NGC 2020 looking down the axis of the stellar outflows, the visualization finishes with a side view that illustrates the nebulas double-lobed structure.
Credit: NASA, ESA, G. Bacon, J. DePasquale, L. Hustak, J. Olmstead, A. Pagan, D. Player, and F. Summers (STScI)
Music: Cosmic Reef by J. DePasquale (STScI) CC BY 4.0")
![Cruising the Cosmic Web, V2 [Dome Version]](https://i.ytimg.com/vi/a9bZ1_YtKWg/hqdefault.jpg "Cruising the Cosmic Web, V2 [Dome Version]
This visualization of a computer simulation showcases the ‘cosmic web’, the large scale structure of the universe. Each bright knot is an entire galaxy, while the purple filaments show where material exists between the galaxies. To the human eye, only the galaxies would be visible, and this visualization allows us to see the strands of material connecting the galaxies and forming the cosmic web.
This visualization is based on a scientific simulation of the growth of structure in the universe. The matter, dark matter, and dark energy in a region of the universe are followed from very early times of the universe through to the present day using the equations of gravity, hydrodynamics, and cosmology. The normal matter has been clipped to show only the densest regions, which are the galaxies, and is shown in white. The dark matter is shown in purple. The size of the simulation is a cube with a side length of 134 megaparsecs (437 million light-years).
The camera choreography is a straight line path through the simulation. The camera accelerates from a standstill at the start, flies at a constant speed, and then decelerates to a stop at the end. The “cruising speed” of the camera is 250,000 parsecs per frame, or about 20 million light-years per second (at 24 frames per second). That’s more than 600 trillion times the speed of light. Buckle your seatbelts.
The simulation is periodic, and the camera flies through it several times. A skew angle is used to avoid showing the same structures on each fly through. The camera path (after accelerating to full speed) does repeat every 2000 frames. Hence, one can get an infinite loop by showing the frames 100 - 2099 over and over.
Visualization: Frank Summers, Space Telescope Science Institute
Simulation: Martin White and Lars Hernquist, Harvard University")
