The Hubble Space Telescope. A new window on the universe

IEE Review ◽  
1990 ◽  
Vol 36 (4) ◽  
pp. 128
Author(s):  
Mark Williamson
Keyword(s):  
Hubble Space Telescope ◽  
Space Telescope ◽  
The Universe

scholarly journals The Evolution of Neutral Gas in the Universe

2006 ◽  
Vol 2 (S235) ◽  
pp. 440-440
Author(s):  
David Turnshek ◽  
Sandhya Rao ◽  
Eric Monier ◽  
Daniel Nestor ◽  
Anna Quider
Keyword(s):  
Absorption Line ◽  
Hubble Space Telescope ◽  
Reference List ◽  
Space Telescope ◽  
Neutral Gas ◽  
The Universe ◽  
Initial Results ◽  
Gas Component

AbstractWe give references to some of our work on the properties and evolution of the neutral gas component of the Universe (see reference list). The bulk of the observed neutral gas has been detected by identifying intervening damped Lyα (DLA) quasar absorption-line systems with N(H) ≥2 × 1020 atoms cm−2. We also present some initial results from a program to identify DLA absorbers near redshift z = 0.5 using Hubble Space Telescope ACS prism spectra (see Figure 1).

scholarly journals Probing the faintest galaxy population at the epoch of reionization with gravitational lensing

2019 ◽  
Vol 15 (S352) ◽  
pp. 26-26
Author(s):  
Hakim Atek
Keyword(s):  
Gravitational Lensing ◽  
Hubble Space Telescope ◽  
Space Telescope ◽  
Systematic Uncertainties ◽  
James Webb Space Telescope ◽  
Exciting Opportunity ◽  
Complete Dataset ◽  
Galaxy Populations ◽  
Galaxy Population ◽  
The Universe

AbstractUltra-deep observations of blank fields with the Hubble Space Telescope have made important inroads in characterizing galaxy populations at redshift z = 6 – 10. Gravitational lensing by massive galaxy clusters offers a new route to identify the faintest sources at the epoch of reionization. In particular, thanks to the Hubble Frontier Fields program, we robustly pushed the detection limit down to MAB = − 15 mag at z ∼ 6. I will present the latest results based on the complete dataset of the HFF clusters and parallel fields, and their implications on the ability of galaxies to reionize the Universe. I will also discuss the results of a comprehensive end-to-end modeling effort towards constraining the systematic uncertainties of the lens models, which are currently the last hurdle before extending the UV LF to fainter luminosities. Finally, I will discuss the great discoveries awaiting combination of such cosmic lenses with the upcoming James Webb Space Telescope and the exciting opportunity to probe the turnover of the UV LF, hence the limit of the star formation process at those early epochs.

scholarly journals Learning to Denoise Astronomical Images with U-nets

2020 ◽  
Author(s):  
Antonia Vojtekova ◽  
Maggie Lieu ◽  
Ivan Valtchanov ◽  
Bruno Altieri ◽  
Lyndsay Old ◽  
...  
Keyword(s):  
Information Gain ◽  
Hubble Space Telescope ◽  
Signal To Noise Ratio ◽  
Post Processing ◽  
Space Telescope ◽  
Noise Characteristics ◽  
Astronomical Imaging ◽  
Average Flux ◽  
Astronomical Images ◽  
The Universe

Abstract Astronomical images are essential for exploring and understanding the universe. Optical telescopes capable of deep observations, such as the Hubble Space Telescope, are heavily oversubscribed in the Astronomical Community. Images also often contain additive noise, which makes de-noising a mandatory step in post-processing the data before further data analysis. In order to maximise the efficiency and information gain in the post-processing of astronomical imaging, we turn to machine learning. We propose Astro U-net, a convolutional neural network for image de-noising and enhancement. For a proof-of-concept, we use Hubble space telescope images from WFC3 instrument UVIS with F555W and F606W filters. Our network is able to produce images with noise characteristics as if they are obtained with twice the exposure time, and with minimum bias or information loss. From these images, we are able to recover $95.9\%$ of stars with an average flux error of $2.26\%$. Furthermore the images have, on average, 1.63 times higher signal-to-noise ratio than the input noisy images, equivalent to the stacking of at least 3 input images, which means a significant reduction in the telescope time needed for future astronomical imaging campaigns.

scholarly journals Gravitational Microlensing of Giant Luminous Arcs: a Test for Compact Dark Matter in Clusters of Galaxies

2001 ◽  
Vol 18 (2) ◽  
pp. 182-185
Author(s):  
Geraint F. Lewis
Keyword(s):  
Dark Matter ◽  
Gravitational Lensing ◽  
Surface Brightness ◽  
Hubble Space Telescope ◽  
Stellar Mass ◽  
Compact Objects ◽  
Clusters Of Galaxies ◽  
True Nature ◽  
Space Telescope ◽  
The Universe

AbstractThe true nature of dark matter in the universe still eludes us. This paper discusses a new test for the detection of stellar mass compact dark matter in galaxy clusters by observing its gravitational lensing influence on the surface brightness of giant luminous arcs. If dark matter is in the form of stellar mass compact objects, then the extremes of such variability are accessible to a monitoring campaign with the Hubble Space Telescope. With the advent of the Next Generation Space Telescope, cluster dark matter in the form of compact objects will induce a ubiquitous ‘shimmering’ of the giant arcs.

scholarly journals The H0 Key Project: Cepheids in NGC925, M101 and M100

1995 ◽  
Vol 155 ◽  
pp. 258-259
Author(s):  
S. M. G. Hughes
Keyword(s):  
Standard Model ◽  
Hubble Space Telescope ◽  
Big Bang ◽  
Distance Scale ◽  
Space Telescope ◽  
The Standard Model ◽  
Age Of The Universe ◽  
Extragalactic Distance Scale ◽  
The Big Bang ◽  
The Universe

AbstractAs part of the Extragalactic Distance Scale Key Project, the Hubble Space Telescope has been used to identify Cepheids in M100, M101 and NGC925, and to measure distances derived from the Cepheid PL relation. For M100, the distance of 17.1 ± 1.8 Mpc has been used to infer a preliminary value for H0 of ~ 80 km/s/Mpc, which brings the age of the Universe derived from the standard model of the Big Bang into conflict with the ages of the oldest stars.

scholarly journals The Invisible Universe

2012 ◽  
Vol 16 (1 and 2) ◽  
pp. 255-259
Author(s):  
Michael Rowan-Robinson
Keyword(s):  
Milky Way ◽  
Hubble Space Telescope ◽  
Space Telescope ◽  
X Ray ◽  
The Past ◽  
Night Sky ◽  
William Herschel ◽  
The Universe ◽  
Optical Telescopes ◽  
The Invisible

With our own eyes we can see the night sky of the stars, planets and the Milky Way, the arena of pre-telescopic astronomy. Modern optical telescopes have opened up the universe of galaxies and we are familiar with the superb images of the Hubble Space Telescope. But with the invisible wavelengths of radio, infrared and X-ray, a very different universe comes into view. The astronomy of the invisible wavelengths was inaugurated by William Herschel in 1800 but developed very slowly over the next 160 years. The past fifty years have seen an explosion in our understanding of this strange world.

scholarly journals Massive stars in extremely metal-poor galaxies: a window into the past

2021 ◽  
Author(s):  
Miriam Garcia ◽  
Christopher J. Evans ◽  
Joachim M. Bestenlehner ◽  
Jean Claude Bouret ◽  
Norberto Castro ◽  
...  
Keyword(s):  
Metal Content ◽  
Hubble Space Telescope ◽  
Massive Stars ◽  
Current Knowledge ◽  
Single Point ◽  
White Paper ◽  
Host Galaxies ◽  
New Paradigm ◽  
Space Telescope ◽  
The Universe

AbstractCosmic history has witnessed the lives and deaths of multiple generations of massive stars, all of them invigorating their host galaxies with ionizing photons, kinetic energy, fresh material, and stellar-mass black holes. Ubiquitous engines as they are, astrophysics needs a good understanding of their formation, evolution, properties and yields throughout the history of the Universe, and with decreasing metal content mimicking the environment at the earliest epochs. Ultimately, a physical model that could be extrapolated to zero metallicity would enable tackling long-standing questions such as “What did the first, very massive stars of the Universe look like?” or “What was their role in the re-ionization of the Universe?” Yet, most of our knowledge of metal-poor massive stars is drawn from one single point in metallicity. Massive stars in the Small Magellanic Cloud (SMC, $\sim $ ∼ 1/5Z⊙ ) currently serve as templates for low-metallicity objects in the early Universe, even though significant differences with respect to massive stars with poorer metal content have been reported. This White Paper summarizes the current knowledge on extremely (sub-SMC) metal poor massive stars, highlighting the most outstanding open questions and the need to supersede the SMC as standard. A new paradigm can be built from nearby extremely metal-poor galaxies that make a new metallicity ladder, but massive stars in these galaxies are out of reach to current observational facilities. Such a task would require an L-size mission, consisting of a 10m-class space telescope operating in the optical and the ultraviolet ranges. Alternatively, we propose that ESA unites efforts with NASA to make the LUVOIR mission concept a reality, thus continuing the successful partnership that made the Hubble Space Telescope one of the greatest observatories of all time.

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