Webb's First Deep Field (NIRSpec MSA Emission Spectra)

 Webb's First Deep Field (NIRSpec MSA Emission Spectra)

NASA’s Webb Telescope has yet another discovery machine aboard – the Near-Infrared Spectrograph’s (NIRSpec’s) microshutter array. This instrument has more than 248,000 tiny doors that can be individually opened to gather spectra (light) of up to approximately 150 individual objects simultaneously.

Of the thousands of distant galaxies behind galaxy cluster SMACS 0723, NIRSpec observed 48 individually – all at the same time – in a field that is approximately the size of a grain of sand held at arm’s length. Quick analysis made it immediately clear that several of these galaxies were observed as they existed at very early periods in the history of the universe, which is estimated to be 13.8 billion years old.

Look for the same feature highlighted in each spectrum. Three lines appear in the same order every time – one hydrogen line followed by two ionized oxygen lines. Where this pattern falls on each spectrum tells researchers the redshift of individual galaxies, revealing how long ago their light was emitted.

Light from the farthest galaxy shown traveled 13.1 billion years before Webb’s mirrors captured it. These observations mark the first time these particular emission lines have been seen at such immense distances – and these are only Webb’s initial observations. There may be even more distant galaxies in this image!

In these spectra, Webb has also shown us the chemical composition of galaxies in the very early universe for the first time. This was made possible by the telescope’s position in space – far away from Earth’s atmosphere, which filters out some infrared light – and its specialization in gathering high-resolution near-infrared light.

And since similar spectra from galaxies at closer distances have long been studied by other space- and ground-based observatories, astronomers already know a lot about the properties of nearby galaxies. Now, astronomers will be able to study and compare spectra from Webb to determine how galaxies have changed over billions of years, dating back to the early universe.

With Webb’s data, researchers can now measure each galaxy’s distance, temperature, gas density, and chemical composition. We will soon learn an incredible amount about galaxies that existed all across cosmic time!

Want to capture your own spectra with Webb’s microshutter array? Learn how scientists use the instrument by “taking” your own observations with this interactive and analyze the spectra it returns.

For a full array of Webb’s first images and spectra, including downloadable files, please visit: https://webbtelescope.org/news/first-images 

NIRSpec was built for the European Space Agency (ESA) by a consortium of European companies led by Airbus Defence and Space (ADS) with NASA’s Goddard Space Flight Center providing its detector and micro-shutter subsystems.




About The Object
Constellation Volans
Distance In order from top to bottom, the four highlighted galaxies are at redshifts of 2.74, 5.27, 7.65 and 8.49.
About The Data
Data Description This image was created with Webb data from proposal . It is part of Webb Early Release Observations. The Early Release Observations and associated materials were developed, executed, and compiled by the ERO production team: Jaclyn Barrientes, Claire Blome, Hannah Braun, Matthew Brown, Margaret Carruthers, Dan Coe, Joseph DePasquale, Nestor Espinoza, Macarena Garcia Marin, Karl Gordon, Alaina Henry, Leah Hustak, Andi James, Ann Jenkins, Anton Koekemoer, Stephanie LaMassa, David Law, Alexandra Lockwood, Amaya Moro-Martin, Susan Mullally, Alyssa Pagan, Dani Player, Klaus Pontoppidan, Charles Proffitt, Christine Pulliam, Leah Ramsay, Swara Ravindranath, Neill Reid, Massimo Robberto, Elena Sabbi, Leonardo Ubeda.  The EROs were also made possible by the foundational efforts and support from the JWST instruments, STScI planning and scheduling, Data Management teams, and Office of Public Outreach.
Instrument NIRCam, NIRSpec
About The Object
Object Name A name or catalog number that astronomers use to identify an astronomical object.
Object Description The type of astronomical object.
R.A. Position Right ascension – analogous to longitude – is one component of an object's position.
Dec. Position Declination – analogous to latitude – is one component of an object's position.
Constellation One of 88 recognized regions of the celestial sphere in which the object appears.
Distance The physical distance from Earth to the astronomical object. Distances within our solar system are usually measured in Astronomical Units (AU). Distances between stars are usually measured in light-years. Interstellar distances can also be measured in parsecs.
Dimensions The physical size of the object or the apparent angle it subtends on the sky.
About The Data
Data Description
  • Proposal: A description of the observations, their scientific justification, and the links to the data available in the science archive.
  • Science Team: The astronomers who planned the observations and analyzed the data. "PI" refers to the Principal Investigator.
Instrument The science instrument used to produce the data.
Exposure Dates The date(s) that the telescope made its observations and the total exposure time.
Filters The camera filters that were used in the science observations.
About The Image
Image Credit The primary individuals and institutions responsible for the content.
Publication Date The date and time the release content became public.
Color Info A brief description of the methods used to convert telescope data into the color image being presented.
Orientation The rotation of the image on the sky with respect to the north pole of the celestial sphere.