the first images open a new era of astronomy

From them nebulaea group of galaxiesa La question des exoplanètes est très ancienne dans l’astronomie. Leur existence est pour la première fois attestée de façon indirecte dans…” data-image=”” data-url=”” data-more=”Lire la suite”>exoplaneta cluster of galaxies and a deep field are therefore the first images and spectral of James Webb Space Telescope that have been introduced and start science operations. This new era that is dawning for astronomy has been unanimously welcomed by the scientific community, which expects significant advances in many fields.

James-Webb is the result of an international partnership between the POTESA and the Canadian Space Agency (Par le biais de son secteur d’activités désigné « Connaissances spatiales, applications et développement industriel…” data-url=”” data-more=”Lire la suite”>ASC). « These first images and spectra from Webb are a great celebration of the international collaboration that made this ambitious mission possible.said Josef Aschbacher, ESA Director General. I want to thank everyone involved in getting this magnificent telescope up and running and publishing these incredible first Webb images – they made this historic day a reality. In addition to launch services, ESA contributed to two of the four science instruments (the NIRSpec and the optical assembly of the Miri instrument), and provides the necessary personnel for mission operations at a total cost of 700 million euros. In exchange for this investment, Europe is guaranteed a minimum of 15% of the observing time but, for the first observing cycle, due to the quality of the observation requests from the astronomers Europeans, the share allocated to European scientists is around 30%.

The SMACS 0723 deep field to the edge of the universe

The first image to be released is the deep field SMACS 0723 whose close observation tells a story of theL’histoire de l’univers commence il y a quelque 13,7 milliards d’années dans une soupe extrêmement dense et chaude. Les lois de la physique telles que nous les…” data-image=”” data-url=”” data-more=”Lire la suite”>Universe in all ages, beginning 13.8 billion years ago. This deep field uses the gravitational lens of a galaxy cluster to reveal some of the most distant galaxies ever detected. With an exposure time of just 12.5 hours, this image only scratches the surface of Webb’s abilities to study deep fields. Some of the objects visible in this image are more than 13 billion years old, confirmed Pierre Ferruit, ESA’s JWST program manager. They formed only a few hundred million years after the big Bang. Fast reading of the data from this image does not allow us to date with certainty objects formed only a few hundred million years after the Big Bang. A deeper analysis of the image is necessary to have an accurate dating. In the coming months, other deep fields will be produced, with longer exposure times, some of them identical to those ofHubble and everything indicates that James-Webb will discover galaxies only a hundred million years old.

A planetary nebula in our neighborhood

From the birth to the death of a planetary nebula, James-Webb can explore the dust and gas since stars aging that could one day become a new star or planet. It is worth remembering that the NIRCam and Miri instruments complement each other very well. The former will provide images with a very good level of detail and very fine reproduction. It is very suitable for observing hot objects such as galaxies. On the contrary, you will see the dust less well, colder. As for Miri, her main interest is that the stars in her field of vision tend to disappear. Therefore, this instrument is very useful for observing very cold objects, including dust, and finding the La lumière blanche
Les longueurs d’ondes de la lumière visible s’échelonnent d’environ 380 nm (violet) à 780 nm (rouge). Le spectre visible est…” data-image=”” data-url=”” data-more=”Lire la suite”>light
galaxies that are so old that they no longer emit in the visible.

A spectrum that changes the era of planetary spectroscopy

James-Webb has detected water molecules on an exoplanet that are obviously not a clue to extraterrestrial life. The interest of this spectrum is to demonstrate much of the remarkable capabilities of the instrument. NIRISS. Remarkable because it is the spectrum in theinfrared of an exoplanet the most detailed ever collected, the first spectrum to include wavelengths more than 1.6 microns in a resolution and precision, and the first to cover the entire wavelength range from 0.6 microns (visible red light) to 2.8 microns (near infrared) in a single shot.

James-Webb will now study hundreds of other systems to find out what the others are made of. atmospheres planetary. Among the observation campaigns already approved, the fine characterization of large organic molecules in the Orion Nebulathe atmosphere of brown dwarfs and observation of several planetary systems, including Trappist-1b. the little one trappist star-1at 40 Light years of us, has the peculiarity that it has a fascinating planetary system: seven planets similar to the earth, three of which have orbits included among those of Venus and March.

Star formation, a strong James-Webb theme

Stars drift and contribute massive amounts of gas and dust, swirling around galaxies. Dust evolves over time, and Webb can study nearby dynamically interacting galaxies to see dust in action. Now scientists can glimpse, in unprecedented detail, how interacting galaxies trigger star formation in one another and how the gas in these galaxies is affected. To get a precise idea of ​​the performance of the James-Webb, download the images from the European Space Agency’s JWST site by clicking on ici and wander around the image.

The complementarity of instruments, one of the strengths of James-Webb

By looking at this star-forming region and others like it, scientists can, thanks to James-Webb, see newly formed stars and study the gas and dust that formed them.

The lower image is a composite made from images acquired by the Near Infrared Instruments (NIRCam) and the Mid Infrared Instrument (Miri). By merging the data from the two instruments, the details are revealed.

Comparing James-Webb images to Hubble isn’t as simple as it seems

Comparison of the James-Webb images with those from Hubble still has limits because the two space observatories do not observe at the same wavelengths and do not use the same wavelengths. Quelquefois, la couleur…” data-image=”” data-url=”” data-more=”Lire la suite”>colors. This explains why certain objects are more present in the Webb images, particularly red-emitting galaxies, than in the Hubble images.

You should also know that more distant galaxies are not visible to Hubble because they are redshifted or located behind in the La formation des nuages
La quantité…” data-image=”” data-url=”” data-more=”Lire la suite”>clouds
very dense powder. Added to this is that Webb’s sensitivity is such that in all his images we will see background galaxies! So you have to be very careful when comparing them.

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