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NASA NTRS2009

Near-UV Sources in the Hubble Ultra Deep Field: The Catalog

The catalog from the first high resolution U-band image of the Hubble Ultra Deep Field, taken with Hubble s Wide Field Planetary Camera 2 through the F300W filter, is presented. We detect 96 U-band objects and compare and combine this catalog with a Great Observatories Origins Deep Survey (GOODS) B-selected catalog that provides B, V, i, and z photometry, spectral types, and photometric redshifts. We have also obtained Far-Ultraviolet (FUV, 1614 Angstroms) data with Hubble s Advanced Camera for Surveys Solar Blind Channel (ACS/SBC) and with Galaxy Evolution Explorer (GALEX). We detected 31 sources with ACS/SBC, 28 with GALEX/FUV, and 45 with GALEX/NUV. The methods of observations, image processing, object identification, catalog preparation, and catalog matching are presented.

Gardner, Jonathan P.↗

NASA NTRS2009

Studying Galaxy Formation with the Hubble, Spitzer and James Webb Space Telescopes

The deepest optical to infrared observations of the universe include the Hubble Deep Fields, the Great Observatories Origins Deep Survey and the recent Hubble Ultra-Deep Field. Galaxies are seen in these surveys at redshifts z greater than 6, less than 1 Gyr after the Big Bang, at the end of a period when light from the galaxies has reionized Hydrogen in the inter-galactic medium. These observations, combined with theoretical understanding, indicate that the first stars and galaxies formed at z greater than 10, beyond the reach of the Hubble and Spitzer Space Telescopes. To observe the first galaxies, NASA is planning the James Webb Space Telescope (JWST), a large (6.5m), cold (less than 50K), infrared-optimized observatory to be launched early in the next decade into orbit around the second Earth-Sun Lagrange point. JWST will have four instruments: The Near-Infrared Camera, the Near-Infrared multi-object Spectrograph, and the Tunable Filter Imager will cover the wavelength range 0.6 to 5 microns, while the Mid-Infrared Instrument will do both imaging and spectroscopy from 5 to 28.5 microns. In addition to JWST's ability to study the formation and evolution of galaxies, I will also briefly review its expected contributions to studies of the formation of stars and planetary systems, and discuss recent progress in constructing the observatory.

Gardner, Jonathan P.↗

NASA NTRS2009

A Scientific Revolution: The Hubble and James Webb Space Telescopes

Astronomy is going through a scientific revolution, responding to a flood of data from the Hubble Space Telescope, other space missions, and large telescopes on the ground. In this talk, I will discuss the top 10 astronomical discoveries of the last 10 years, and the role that space telescopes have played in those discoveries. The next decade looks equally bright with the newly refurbished Hubble and the promise of its successor, the James Webb Space Telescope. I will describe how Hubble was upgraded and how and why we are building Webb.

Gardner, Jonathan P.↗

NASA NTRS1999

Hubble Space Telescope: Servicing Mission 3A. Media Reference Guide

Since its launch in April 1990, the Hubble Space Telescope (HST) has provided scientific data and images of unprecedented resolution from which many new and exciting discoveries have been made. The Telescope's purpose is to spend 20 years probing the farthest and faintest reaches of the cosmos. Crucial to fulfilling this objective is a series of on-orbit manned servicing missions. The First Servicing Mission (SM1) took place in December 1993 and the Second Servicing Mission (SM2) was flown in February 1997. During these missions, astronauts perform planned repairs and maintenance activities to restore and upgrade the observatory s capabilities. To facilitate this process, the Telescope s designers configured science instruments and several vital engineering subsystems as Orbital Replacement Units (ORU) -- modular packages with standardized fittings accessible to astronauts in pressurized suits. Hubble's Third Servicing Mission has been separated into two parts: Servicing Mission 3A (SM3A) will fly in Fall of 1999 and Servicing Mission 3B (SM3B) is planned for 2001. The principal objective of SM3A is to replace all six gyroscopes that compose the three Rate Sensor Units (RSU). In addition, space-walking astronauts will install a new Advanced Computer that will dramatically increase the computing power, speed, and storage capability of HST. They will change out one of the Fine Guidance Sensors (FGS) and replace a tape recorder with a new Solid State Recorder (SSR). The Extravehicular Activity (EVA) crew also will install a new S-band Single-Access Transmitter (SSAT), and Voltage/Temperature Improvement Kits (VIK) for the Telescope s nickel-hydrogen batteries. Finally, they will begin repair of the multilayer insulation on Hubble s outer surface. During SM3B astronauts will install a new science instrument, the Advanced Camera for Surveys (ACS), and an Aft Shroud Cooling System (ASCS) for the other axial science instruments. They will attach a new cryogenic cooler to the Near-Infrared Camera and Multi-Object Spectrometer (NICMOS). They also will replace the HST flexible Solar Arrays with new high-performance rigid arrays.

FROM↗

NASA NTRS2011

Eyes on the Universe: The Legacy of the Hubble Space Telescope and Looking to the Future with the James Webb Space Telescope

Over the past 20 years the Hubble Space Telescope has revolutionized our understanding of the Universe. Most recently, the complete refurbishment of Hubble in 2009 has given new life to the telescope and the new science instruments have already produced groundbreaking science results, revealing some of the most distant galaxy candidates ever discovered. Despite the remarkable advances in astrophysics that Hubble has provided, the new questions that have arisen demand a new space telescope with new technologies and capabilities. I will present the exciting new technology development and science goals of NASA's James Webb Space Telescope, which is currently being built and tested and will be launched this decade.

Straughn, Amber↗

NASA NTRS2011

A Scientific Revolution: The Hubble and James Webb Space Telescopes

Astronomy is going through a scientific revolution, responding to a flood of data from the Hubble Space Telescope, other space missions, and large telescopes on the ground. In this talk, I will discuss some of the most important astronomical discoveries of the last 10 years, and the role that space telescopes have played in those discoveries. The next decade looks equally bright with the newly refurbished Hubble and the promise of its successor, the James Webb Space Telescope. I will describe how Hubble was upgraded and how and why we are building Webb.

Gardner, Jonathan↗

NASA NTRS2011

Eyes on the Universe: The Legacy of the Hubble Space Telescope and Looking to the Future with the James Webb Space Telescope

Straughn, Amber↗

NASA NTRS2011

A Scientific Revolution: the Hubble and James Webb Space Telescopes

Astronomy is going through a scientific revolution, responding to a flood of data from the Hubble Space Telescope, other space missions, and large telescopes on the ground. In this talk, I will discuss some of the most important astronomical discoveries of the last 10 years, and the role that space telescopes have played in those discoveries. The next decade looks equally bright with the newly refurbished Hubble and the promise of its successor, the James Webb Space Telescope. I will describe how Hubble was upgraded and how and why we are building Webb.

Gardner, Jonathan P.↗

NASA NTRS2011

Hubble Space Telescope and James Webb Space Telescope

Over the past 20 years the Hubble Space Telescope has revolutionized our understanding of the Universe. Most recently, the complete refurbishment of Hubble in 2009 has given new life to the telescope and the new science instruments have already produced ground breaking science results, revealing some of the most distant galaxy candidates ever discovered. Despite the remarkable advances in astrophysics that Hubble has provided, the new questions that have arisen demand a new space telescope with new technologies and capabilities. I will present the exciting new technology development and science goals of NASA's James Webb Space Telescope, which is currently being built and tested and will be launched this decade.

Straughn, Amber↗

NASA NTRS2012

A Scientific Revolution: the Hubble and James Webb Space Telescopes

Astronomy is going through a scientific revolution, responding to a flood of data from the Hubble Space Telescope, other space missions, and large telescopes on the ground. In this talk, I will discuss some of the most important astronomical discoveries of the last IO years, and the role that space telescopes have played in those discoveries. The next decade looks equally bright with the newly refurbished Hubble and the promise of its successor, the James Webb Space Telescope. I will describe how Hubble was upgraded and how and why we are building Webb.

Gardner, Jonathan P.↗

NASA NTRS2024

Zonal and Regional Jupiter Brightness Trends from the Hubble Outer Planet Atmospheres Legacy Program

The Hubble Outer Planet Atmospheres Legacy (OPAL) program began in 2014 and has observed Jupiter yearly from 2015 to 2024. Using high spatial resolution imaging from the Hubble Wide Field Camera 3, brightness trends were investigated focusing on the unique UV capability and absolute calibration consistency of the Hubble Space Telescope. From these data, a 4- to 5- year period is observed at 24° N, particularly in the blue (F395N) and methane gas absorption (FQ889N) filters. Additionally, several wavelengths show a potential seasonal periodicity, especially at the equator, but more years of data are needed to confirm this trend over multiple Jupiter years. Variability in Oval BA and the Great Red Spot brightness is not cyclical, but these two anticyclonic features show changes on a yearly timescale.

Amy A Simon↗

NASA NTRS1994

Distance to the Virgo Cluster Galaxy M100 from Hubble Space Telescope Observations of Cepheids

Accurate distances to galaxies are critical to determining the present expansion rate of the Universe or Hubble Constant (H(sub 0)). An important step in resolving the current uncertainty in H(sub 0) is the measurement of the distance to the Virgo cluster of galaxies. New observations using the Hubble Space Telescope yield a distance of 17.1 +/- 1.8 Mpc to the Virgo cluster galaxy M100. This distance leads to a value of H(sub 0) = 17 km/sec/Mpc. A comparable value of H(sub 0) is also derived from the Coma cluster using independent estimates of its distance ratio relative to the Virgo cluster.

cluster expansion rate↗

DOE OSTI2020

Super-CMB fluctuations and the Hubble tension

We study the covariance in the angular power spectrum estimates of CMB fluctuations when the primordial fluctuations are non-Gaussian. The non-Gaussian covariance comes from a nonzero connected four-point correlation function -- or the trispectrum in Fourier space -- and can be large when long-wavelength (super-CMB) modes are strongly coupled to short-wavelength modes. The effect of such non-Gaussian covariance can be modeled through additional freedom in the theoretical CMB angular power spectrum and can lead to different inferred values of the standard cosmological parameters relative to those in ΛCDM. Taking the collapsed limit of the primordial trispectrum in the quasi-single field inflation model as an example, we study how the six standard ΛCDM parameters shift when two additional parameters describing the trispectrum are allowed. The reduced statistical significance of the Hubble tension in the extended model allows us to combine the {\it Planck} temperature data and the type Ia supernovae data from Panstarrs with the distance-ladder measurement of the Hubble constant. Here, this combination of data shows strong evidence for a primordial trispectrum-induced non-Gaussian covariance, with a likelihood improvement of Δχ 2 ≈ –15 (with two additional parameters) relative to ΛCDM.

79 ASTRONOMY AND ASTROPHYSICS↗

DOE OSTI2021

Large-scale Gravitational Lens Modeling with Bayesian Neural Networks for Accurate and Precise Inference of the Hubble Constant

We investigate the use of approximate Bayesian neural networks (BNNs) in modeling hundreds of time delay gravitational lenses for Hubble constant (H 0 ) determination. Here, our BNN was trained on synthetic Hubble Space Telescope quality images of strongly lensed active galactic nuclei with lens galaxy light included. The BNN can accurately characterize the posterior probability density functions (PDFs) of model parameters governing the elliptical power-law mass profile in an external shear field. We then propagate the BNN-inferred posterior PDFs into an ensemble H 0 inference, using simulated time delay measurements from a plausible dedicated monitoring campaign. Assuming well-measured time delays and a reasonable set of priors on the environment of the lens, we achieve a median precision of 9.3% per lens in the inferred H 0 . A simple combination of a set of 200 test lenses results in a precision of 0.5 km s –1 Mpc –1 (0.7%), with no detectable bias in this H 0 recovery test. The computation time for the entire pipeline—including the generation of the training set, BNN training and H0 inference—translates to 9 minutes per lens on average for 200 lenses and converges to 6 minutes per lens as the sample size is increased. Being fully automated and efficient, our pipeline is a promising tool for exploring ensemble-level systematics in lens modeling for H 0 inference.

79 ASTRONOMY AND ASTROPHYSICS↗

NASA NTRS1996

The Extragalactic Distance Scale Key Project VIII. The Discovery of Cepheids and a New Distance to NGC 3621 Using the Hubble Space Telescope

We report on the discovery of Cepheids in the field spiral galaxy NGC3621, based on observations made with the Wide Field and Planetary Camera 2 on board the Hubble Space Telescope (HST). NGC 3621 is one of 18 galaxies observed as part of the HST Key Project on the Extragalctic Distance Scale, which aims to measure the Hubble Constant to 10 percent accuracy.

galaxies NGC 3621 stars cepheids Hubble constant↗

NASA NTRS2009

Hubble 2008: Science Year in Review

Hubbles remarkable mission has now spanned 18 years. During that time, it has been at the nexus of perhaps the most exciting period of discovery in the history of astronomy. Simultaneously, Hubble has offered up some of the most daunting engineering challenges to humans working in space, and success in meeting those challenges has been among NASAs greatest triumphs.

Hubble space telescope↗

NASA NTRS2013

Hubble Tarantula Treasury Project: Unraveling Tarantula's Web. I. Observational Overview and First Results

The Hubble Tarantula Treasury Project (HTTP) is an ongoing panchromatic imaging survey of stellar populations in the Tarantula Nebula in the Large Magellanic Cloud that reaches into the sub-solar mass regime (<0.5 Stellar Mass). HTTP utilizes the capability of the Hubble Space Telescope to operate the Advanced Camera for Surveys and the Wide Field Camera 3 in parallel to study this remarkable region in the near-ultraviolet, optical, and near-infrared spectral regions, including narrow-band H(alpha) images. The combination of all these bands provides a unique multi-band view. The resulting maps of the stellar content of the Tarantula Nebula within its main body provide the basis for investigations of star formation in an environment resembling the extreme conditions found in starburst galaxies and in the early universe. Access to detailed properties of individual stars allows us to begin to reconstruct the temporal and spatial evolution of the stellar skeleton of the Tarantula Nebula over space and time on a sub-parsec scale. In this first paper we describe the observing strategy, the photometric techniques, and the upcoming data products from this survey and present preliminary results obtained from the analysis of the initial set of near-infrared observations.

Tarantula↗

DOE OSTI2025

Hints of primordial magnetic fields at recombination and implications for the Hubble tension

Primordial Magnetic Fields (PMFs), long studied as relics of the early Universe, accelerate recombination and have been proposed as a way to relieve the Hubble tension. However, previous studies relied on simplified toy models. Here, in this study, we use recent evaluations of recombination with PMFs, incorporating full magnetohydrodynamic (MHD) simulations and detailed Lyman-alpha radiative transfer, to test PMF-enhanced recombination (bΛCDM) against observational data from the cosmic microwave background (CMB), baryon acoustic oscillations (BAO), and Type Ia supernovae (SN). Focusing on non-helical PMFs with a Batchelor spectrum, we find a preference for presentday total field strengths of approximately 5-10 pico-Gauss. Depending on the dataset combination, this preference ranges from mild (∼ 1.8σ with Planck + DESI) to moderate (∼ 3σ with Planck + DESI + SH0ES-calibrated SN) significance. The bΛCDM has Planck + DESI χ 2 values equal to or better than ΛCDM while predicting a higher Hubble constant. Future high-resolution CMB temperature and polarization measurements will be crucial for confirming or further constraining PMFs at recombination. Field strengths of 5-10 pico-Gauss align closely with those required for cluster magnetic fields to originate entirely from primordial sources, without the need for additional dynamo amplification.

Jedamzik, Karsten [Centre National de la Recherche↗