The space telescope which was opened into low Earth orbit in 1990 recognized as The Hubble Space Telescope was not first of it’s kind but one of the most leading and useful and is well known as both a vital investigation tool and a civic relations blessing for astronomy. The Hubble telescope is named following astronomer Edwin Hubble and is one of NASA’s Great Observatories, along with the Compton Gamma Ray Observatory, the Chandra X-ray Observatory, and the Spitzer Space Telescope.
Hubble features a 2.4-meter (7.9 ft) mirror, and its four key mechanisms observe in the ultraviolet, visible, and near infrared regions of the electromagnetic spectrum. Hubble’s orbit beyond the alteration of Earth’s atmosphere allows it to take exceptionally high-resolution images with significantly lesser background light than ground-built telescopes. It has documented some of the most exhaustive visible light images, permitting a deep view hooked on space. Many Hubble observations have led to innovations in astrophysics, such as determining the rate of development of the universe.
Literature survey
This published research paper is from Neal Dalal, Cora Dvorkin, Jeremy Heyl, Bhuvnesh Jain (Chair), Marc Kamionkowski, Phil Marshall, David Weinberg .
We can list out some key works of this paper as follows:
Hubble’s constant
The Hubble constant H0 is the oldest perceptible of modern cosmology, with the first (badly inaccurate) estimate previously appearing in Hubble’s 1929 paper on the enlarging universe. The HST Key Project (Freedman et al. 2001) achieved a magnitude of H0 with 10% doubt, dramatic increase over the factor-of-two range of values that prevailed earlier HST.
Cepheid calibration of SNIa distances
Cepheid variables are pulsing post-main sequence stars with a precise relationship between their period and brightness. The most precise of the current distance-ladder estimations of H0 use Cepheid variable stars to calibrate the distances to neighboring star-forming galaxies that have hosted well observed SNIa.
Calibrating the distance scale with TRGB stars
As stars arrive at the tip of the red-giant branch (TRGB) they commence helium ablaze. The relationship of the triple-alpha reaction, degeneracy and neutrino losses yields a star with a characteristic luminosity at this stage of its life that is only inadequately sensitive to its composition and mass.
Strong lens time delays
Strong gravitational lens systems with time-variable supplies (like AGN and supernovae) provide a measurement of physical distance out to in-between redshifts, provided the time interruptions between the multiple images in the system can be measured.
Merging galaxy clusters
One attempt to constrain dark matter self-interactions utilizes cosmic collisions between systems rich in dark matter. Massive clusters of galaxies contain dense strengths of dark matter, and when massive gatherings collide, a sensitive probe of the strength of dark matter interactions.
Substructure in galaxy halos Diminutive-scale structure in the spatial division of dark matter has long been recognized as a vulnerable probe of dark matter properties, including its temperature (e.g. Cold vs. Warm DM) or magnitude scale (as in Fuzzy DM). The abundance of low-mass underside in the dark matter halos bordering typical galaxies is vulnerable to a variety of DM physics, and may be used to search for differences from the standard Cold Dark Matter model.
Role of physics
It’s fundamentally the construction of the space telescope and how it’s used to collect the data is completely related to physics. Let’s now see about the construction of the Hubble Space Telescope.
Construction Telescope assembly (optical)
The HST is a Cassegrain reflector of Ritchey–Chrétien design, as are extremely large professional telescopes. This design, with two hyperbolic mirrors, is recognized for good imaging performance over a wide field of point of view, with the drawback that the mirrors have shapes that are hard to manufacture and test.
The mirror and optical systems of the telescope determine the finale performance, and they were devised to exacting specifications. Optical telescopes typically have mirrors sophisticated to an accuracy of about a tenth of the wavelength of visible light, but the Space Telescope was to be used for annotations from the visible through the ultraviolet (shorter wavelengths) and was detailed to be diffraction limited to take full advantage of the space environment.
Therefore, its mirror needed to be polished to an accuracy of 10 nanometers (0.4 microinches), or about 1/65 of the wavelength of red light. On the long wavelength end up, the OTA was not fabricated with optimum IR accomplishment in mind—for example, the mirrors are kept at stable (and warm, about 15 °C) temperatures by heaters. This limits Hubble’s performance as an infrared telescope.
Perkin-Elmer intended to use custom-built and exceptionally sophisticated computer-controlled polishing machines to crush the mirror to the required shape. However, in case their cutting-edge equipment ran into complexities, NASA demanded that PE sub-contract to Kodak to construct a back-up mirror using old-fashioned mirror-polishing techniques.
Published data and graph
Velocity–distance relation among extra-galactic nebulae. Circular velocities, amended for solar motion (but labeled in the wrong units), are strategized against distances projected from involved stars and mean luminosities of nebulae in a cluster. The black discs and complete line represent the explanation for solar motion by means of the nebulae individually; the circles and fragmented line represent the solution coalescing the nebulae into groups; the cross represents the mean velocity conforming to the mean distance of 22 nebulae whose distances could not be estimated individually.
Published values of the Hubble constant vs. time. Reconsiderations in Hubble’s original distance scale justification for significant changes in the Hubble constant from 1920 to the present as gathered by John Huchra of the Harvard–Smithsonian Center for Astrophysics. At each epoch, the estimated error in the Hubble constant is small compared with the consequent changes in its value. This result is a symptom of underestimated systematic errors.
The Hubble diagram for type Ia supernovae. From the compilation of well observed type Ia supernovae by Jha (29). The scatter about the line corresponds to statistical distance errors of
Conclusion science highlights
The Space Telescope Science Institute has studied the scientific impact of Hubble observations using two metrics: the number of citations in the professional astronomical literature and references to Hubble discoveries in the popular media.
Ultradeep Images of the Universe—Galaxies in Formation
Hubble looks so far out into space that it observes objects whose light has taken many billions of years to reach us. Astronomers therefore see these objects as they were at some distant time in the past; in effect, Hubble provides a “time machine” that can show us how the universe evolved. The Hubble Ultradeep Field penetrates back more than 12 billion years to within 1 billion years of the Big Bang Infant galaxies can be seen in the process of forming, harbingers of a great wave of star formation that soon afterward bathed the universe in the light of 10 billion trillion stars.
Measurement of the Hubble Constant, the Distance Scale of the Universe
Knowledge of the size and age of the universe had long been uncertain by a factor of two, a level of uncertainty that was a major obstacle to the testing of cosmological theory. Hubble measured the apparent brightness of so-called Cepheid variable star in nearby galaxies and used them to estimate the distances to those galaxies.
Hubble in the scientific and popular press
Nearly 5000 scientific papers have been published based Hubble observations, and the publication rate in refereed journals is currently about 500 per year.
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