Catalogue Search | MBRL
Are you sure you want to remove the book from the shelf?
{{itemTitle}}
140
result(s) for
"Paris, Diego"
Sort by:
A massive interacting galaxy 510 million years after the Big Bang
James Webb Space Telescope observations have spectroscopically confirmed the existence of galaxies as early as 300 Myr after the Big Bang and with a higher number density than what was expected based on galaxy formation models and Hubble Space Telescope observations. Yet, most sources confirmed spectroscopically so far in the first 500 Myr have rest-frame ultraviolet (UV) luminosities below the characteristic luminosity (
M
UV
*
), limiting the signal-to-noise ratio for investigating substructure. Here we present a high-resolution spectroscopic and spatially resolved study of a bright galaxy (
M
UV
= −21.66 ± 0.03,
~
2
M
UV
*
) at a redshift
z
= 9.3127 ± 0.0002 (510 Myr after the Big Bang) with an estimated stellar mass of
1
.
6
−
0.4
+
0.5
×
1
0
9
M
⊙
, forming
1
9
−
6
+
5
solar masses per year and with a metallicity of about one tenth that of solar. The system has a morphology typically associated with two interacting galaxies, with a two-component main clump of very young stars (age less than 10 Myr) surrounded by an extended stellar population (120 ± 20 Myr old, identified from modelling the NIRSpec spectrum) and an elongated clumpy tidal tail. The observations acquired at high spectral resolution identify oxygen, neon and hydrogen emission lines, as well as the Lyman break, where there is evidence of substantial absorption of Lyα. The [O
ii
] doublet is resolved spectrally, enabling an estimate of the electron number density and ionization parameter of the interstellar medium and showing higher densities and ionization than in analogues at lower redshifts. We identify evidence of absorption lines (silicon, carbon and iron), with low confidence individual detections but a signal-to-noise ratio larger than 6 when stacked. These absorption features suggest that Lyα is damped by the interstellar and circumgalactic media. Our observations provide evidence of a rapid and efficient build-up of mass and metals in the immediate aftermath of the Big Bang through mergers, demonstrating that there were massive galaxies with several billion stars at early times.
JWST detections of Si, C and Fe absorption lines in a bright
z
= 9.31 galaxy with a two-component clump structure suggest that mergers contributed to the rapid build-up of mass and chemical enrichment soon after the Big Bang.
Journal Article
The nature of an ultra-faint galaxy in the cosmic dark ages seen with JWST
In the first billion years after the Big Bang, sources of ultraviolet (UV) photons are believed to have ionized intergalactic hydrogen, rendering the Universe transparent to UV radiation. Galaxies brighter than the characteristic luminosity
L
* (refs.
1
,
2
) do not provide enough ionizing photons to drive this cosmic reionization. Fainter galaxies are thought to dominate the photon budget; however, they are surrounded by neutral gas that prevents the escape of the Lyman-α photons, which has been the dominant way to identify them so far. JD1 was previously identified as a triply-imaged galaxy with a magnification factor of 13 provided by the foreground cluster Abell 2744 (ref.
3
), and a photometric redshift of
z
≈ 10. Here we report the spectroscopic confirmation of this very low luminosity (≈0.05
L
*) galaxy at
z
= 9.79, observed 480 Myr after the Big Bang, by means of the identification of the Lyman break and redward continuum, as well as multiple ≳4
σ
emission lines, with the Near-InfraRed Spectrograph (NIRSpec) and Near-InfraRed Camera (NIRCam) instruments. The combination of the James Webb Space Telescope (JWST) and gravitational lensing shows that this ultra-faint galaxy (
M
UV
= −17.35)—with a luminosity typical of the sources responsible for cosmic reionization—has a compact (≈150 pc) and complex morphology, low stellar mass (10
7.19
M
⊙
) and subsolar (≈0.6
Z
⊙
) gas-phase metallicity.
The JWST, with the aid of gravitational lensing, confirms the extreme distance of an ultra-faint galaxy at a redshift of 9.79, showing it to have a luminosity typical of the sources responsible for cosmic reionization and highly compact and complex morphology.
Journal Article
Deep Large Binocular Camera r-band Observations of the GOODS-N Field
We obtained 838 Sloan r-band images (∼28 hr) of the GOODS-North field with the Large Binocular Camera (LBC) on the Large Binocular Telescope in order to study the presence of extended, low surface brightness features in galaxies and investigate the trade-off between image depth and resolution. The individual images were sorted by effective seeing, which allowed for optimal resolution and optimal depth mosaics to be created with all images with seeing FWHM < 0”.9 and FWHM < 2”.0, respectively. Examining bright galaxies and their substructure as well as accurately deblending overlapping objects requires the optimal resolution mosaic, while detecting the faintest objects possible (to a limiting magnitude of m
AB ∼ 29.2 mag) requires the optimal depth mosaic. The better surface brightness sensitivity resulting from the larger LBC pixels, compared to those of extant WFC3/UVIS and ACS/WFC cameras aboard the Hubble Space Telescope allows for unambiguous detection of both diffuse flux and very faint tidal tails. Azimuthally-averaged radial surface brightness profiles were created for the 360 brightest galaxies in each of the two mosaics. On average, these profiles showed minimal difference between the optimal resolution and optimal depth surface brightness profiles. However, ≲15% of the profiles show excess flux in the galaxy outskirts down to surface brightness levels of
μ
r
AB
≃
31
mag arcsec−2. This is relevant to Extragalactic Background Light (EBL) studies as diffuse light in the outer regions of galaxies are thought to be a major contribution to the EBL. While some additional diffuse light exists in the optimal depth profiles compared to the shallower, optimal resolution profiles, we find that diffuse light in galaxy outskirts is a minor contribution to the EBL overall in the r-band.
Journal Article
Ultra-deep Large Binocular Camera U -band Imaging of the GOODS-North Field: Depth Versus Resolution
We present a study of the trade-off between depth and resolution using a large number of U-band imaging observations in the GOODS-North field from the Large Binocular Camera (LBC) on the Large Binocular Telescope (LBT). Having acquired over 30 hr of data (315 images with 5–6 minutes exposures), we generated multiple image mosaics, starting with the best atmospheric seeing images (FWHM ≲ 0″8), which constitute ~10% of the total data set. For subsequent mosaics, we added in data with larger seeing values until the final, deepest mosaic included all images with FWHM ≲ 1″8 (~94% of the total data set). From the mosaics, we made object catalogs to compare the optimal-resolution, yet shallower image to the lower-resolution but deeper image. We show that the number counts for both images are ~90% complete to U AB ≲ 26 mag. Fainter than U AB ~ 27 mag, the object counts from the optimal-resolution image start to drop-off dramatically (90% between U AB = 27 and 28 mag), while the deepest image with better surface-brightness sensitivity (... ≲ 32 mag arcsec−2) show a more gradual drop (10% between U AB sime 27 and 28 mag). For the brightest galaxies within the GOODS-N field, structure and clumpy features within the galaxies are more prominent in the optimal-resolution image compared to the deeper mosaics. We conclude that for studies of brighter galaxies and features within them, the optimal-resolution image should be used. However, to fully explore and understand the faintest objects, the deeper imaging with lower resolution are also required. Finally, we find-for 220 brighter galaxies with U AB ≲ 23 mag-only marginal differences in total flux between the optimal-resolution and lower-resolution light-profiles to ... ≲ 32 mag arcsec−2. In only 10% of the cases are the total-flux differences larger than 0.5 mag. This helps constrain how much flux can be missed from galaxy outskirts, which is important for studies of the Extragalactic Background Light. (ProQuest: ... denotes formulae omitted.)
Journal Article
Deep Large Binocular Camera r-band Observations of the GOODS-N Field
We obtained 838 Sloan r -band images (∼28 hr) of the GOODS-North field with the Large Binocular Camera (LBC) on the Large Binocular Telescope in order to study the presence of extended, low surface brightness features in galaxies and investigate the trade-off between image depth and resolution. The individual images were sorted by effective seeing, which allowed for optimal resolution and optimal depth mosaics to be created with all images with seeing FWHM < 0.″9 and FWHM < 2.″0, respectively. Examining bright galaxies and their substructure as well as accurately deblending overlapping objects requires the optimal resolution mosaic, while detecting the faintest objects possible (to a limiting magnitude of m AB ∼ 29.2 mag) requires the optimal depth mosaic. The better surface brightness sensitivity resulting from the larger LBC pixels, compared to those of extant WFC3/UVIS and ACS/WFC cameras aboard the Hubble Space Telescope allows for unambiguous detection of both diffuse flux and very faint tidal tails. Azimuthally-averaged radial surface brightness profiles were created for the 360 brightest galaxies in each of the two mosaics. On average, these profiles showed minimal difference between the optimal resolution and optimal depth surface brightness profiles. However, ≲15% of the profiles show excess flux in the galaxy outskirts down to surface brightness levels of μ r AB ≃ 31 mag arcsec −2 . This is relevant to Extragalactic Background Light (EBL) studies as diffuse light in the outer regions of galaxies are thought to be a major contribution to the EBL. While some additional diffuse light exists in the optimal depth profiles compared to the shallower, optimal resolution profiles, we find that diffuse light in galaxy outskirts is a minor contribution to the EBL overall in the r -band.
Journal Article
Using mobile sequencers in an academic classroom
The advent of mobile DNA sequencers has made it possible to generate DNA sequencing data outside of laboratories and genome centers. Here, we report our experience of using the MinION, a mobile sequencer, in a 13-week academic course for undergraduate and graduate students. The course consisted of theoretical sessions that presented fundamental topics in genomics and several applied hackathon sessions. In these hackathons, the students used MinION sequencers to generate and analyze their own data and gain hands-on experience in the topics discussed in the theoretical classes. The manuscript describes the structure of our class, the educational material, and the lessons we learned in the process. We hope that the knowledge and material presented here will provide the community with useful tools to help educate future generations of genome scientists.
Journal Article
Ultra-deep Large Binocular Camera U-band Imaging of the GOODS-North Field
We present a study of the trade-off between depth and resolution using a large number of U-band imaging observations in the GOODS-North field from the Large Binocular Camera (LBC) on the Large Binocular Telescope (LBT). Having acquired over 30 hr of data (315 images with 5–6 minutes exposures), we generated multiple image mosaics, starting with the best atmospheric seeing images (FWHM ≲
0
.
′
′
8
), which constitute ∼10% of the total data set. For subsequent mosaics, we added in data with larger seeing values until the final, deepest mosaic included all images with FWHM ≲
1
.
′
′
8
(∼94% of the total data set). From the mosaics, we made object catalogs to compare the optimal-resolution, yet shallower image to the lower-resolution but deeper image. We show that the number counts for both images are ∼90% complete to UAB
≲ 26 mag. Fainter than UAB
∼ 27 mag, the object counts from the optimal-resolution image start to drop-off dramatically (90% between UAB
= 27 and 28 mag), while the deepest image with better surface-brightness sensitivity (
μ
U
A
B
≲
32
mag arcsec−2) show a more gradual drop (10% between UAB
≃ 27 and 28 mag). For the brightest galaxies within the GOODS-N field, structure and clumpy features within the galaxies are more prominent in the optimal-resolution image compared to the deeper mosaics. We conclude that for studies of brighter galaxies and features within them, the optimal-resolution image should be used. However, to fully explore and understand the faintest objects, the deeper imaging with lower resolution are also required. Finally, we find—for 220 brighter galaxies with UAB
≲ 23 mag—only marginal differences in total flux between the optimal-resolution and lower-resolution light-profiles to
μ
U
A
B
≲
32
mag arcsec−2. In only 10% of the cases are the total-flux differences larger than 0.5 mag. This helps constrain how much flux can be missed from galaxy outskirts, which is important for studies of the Extragalactic Background Light.
Journal Article
Ultra-deep Large Binocular Camera U-band Imaging of the GOODS-North Field: Depth Versus Resolution Based on data acquired using the Large Binocular Telescope (LBT)
We present a study of the trade-off between depth and resolution using a large number of U-band imaging observations in the GOODS-North field from the Large Binocular Camera (LBC) on the Large Binocular Telescope (LBT). Having acquired over 30 hr of data (315 images with 5-6 minutes exposures), we generated multiple image mosaics, starting with the best atmospheric seeing images (FWHM 0 8), which constitute ∼10% of the total data set. For subsequent mosaics, we added in data with larger seeing values until the final, deepest mosaic included all images with FWHM 1 8 (∼94% of the total data set). From the mosaics, we made object catalogs to compare the optimal-resolution, yet shallower image to the lower-resolution but deeper image. We show that the number counts for both images are ∼90% complete to UAB 26 mag. Fainter than UAB ∼ 27 mag, the object counts from the optimal-resolution image start to drop-off dramatically (90% between UAB = 27 and 28 mag), while the deepest image with better surface-brightness sensitivity ( U AB 32 mag arcsec−2) show a more gradual drop (10% between UAB 27 and 28 mag). For the brightest galaxies within the GOODS-N field, structure and clumpy features within the galaxies are more prominent in the optimal-resolution image compared to the deeper mosaics. We conclude that for studies of brighter galaxies and features within them, the optimal-resolution image should be used. However, to fully explore and understand the faintest objects, the deeper imaging with lower resolution are also required. Finally, we find-for 220 brighter galaxies with UAB 23 mag-only marginal differences in total flux between the optimal-resolution and lower-resolution light-profiles to U AB 32 mag arcsec−2. In only 10% of the cases are the total-flux differences larger than 0.5 mag. This helps constrain how much flux can be missed from galaxy outskirts, which is important for studies of the Extragalactic Background Light.
Journal Article
Witnessing downsizing in the making: quiescent and breathing galaxies at the dawn of the Universe
[Shortened for arXiv] We conduct a systematic search for \\(\\log(M_\\ast/M_\\odot) \\geq 9.5\\) quiescent galaxies at \\(z > 3\\) in six extragalactic deep fields observed with NIRCam, with the goal of extracting their physical and statistical features in a uniform and self-consistent manner. We exploit the ASTRODEEP-JWST photometric catalogs to single out robust candidates, including sources quenched only a few tens of Myr before the observation. We apply a SED-fitting procedure which explores three functional forms of star formation history and the \\(\\chi^2\\) probabilities of the solutions, with additional checks to minimise the contamination from interlopers, tuning our selection criteria against available spectroscopic data from the DAWN archive and simulated catalogs. We select 633 candidates, which we rank by a reliability parameter based on the probabilities of the quiescent and alternative star-forming solutions, with 291 candidates tagged as \"gold\". According to the best-fit models, 79\\% of the massive (\\(\\log(M_\\ast/M_\\odot) \\geq 10.5\\)) quiescent galaxies at \\(3 < z < 5\\) stopped forming stars at least 150 Myr before the time of observation, while 89\\% of low-mass sources have been quenched for less than 150 Myr. The abundance of low-mass old quiescent systems does not increase significantly with time from \\(z = 5\\) to 3: low-mass objects seem to be experiencing a short episode of quenching followed by rejuvenation (``breathing''), consistent with a downsizing scenario of galaxy formation. We also find an abrupt drop in the density of massive quiescent candidates at \\(z > 5\\). We derive estimates for the number density of early passive galaxies up to \\(z = 10\\) and compare them against various models: tensions with data remain in the modeling of the observed bimodality of time passed since quenching as a function of mass.
Paper