A fundamental quest of modern astronomy is to locate the earliest galaxies and study how they influenced the intergalactic medium a few hundred million years after the Big Bang
. The abundance of ...star-forming galaxies is known to decline
from redshifts of about 6 to 10, but a key question is the extent of star formation at even earlier times, corresponding to the period when the first galaxies might have emerged. Here we report spectroscopic observations of MACS1149-JD1
, a gravitationally lensed galaxy observed when the Universe was less than four per cent of its present age. We detect an emission line of doubly ionized oxygen at a redshift of 9.1096 ± 0.0006, with an uncertainty of one standard deviation. This precisely determined redshift indicates that the red rest-frame optical colour arises from a dominant stellar component that formed about 250 million years after the Big Bang, corresponding to a redshift of about 15. Our results indicate that it may be possible to detect such early episodes of star formation in similar galaxies with future telescopes.
Abstract
We report a massive quiescent galaxy at
z
spec
=
3.0922
−
0.004
+
0.008
spectroscopically confirmed at a protocluster in the SSA22 field by detecting the Balmer and Ca
ii
absorption features ...with the multi-object spectrometer for infrared exploration on the Keck I telescope. This is the most distant quiescent galaxy confirmed in a protocluster to date. We fit the optical to mid-infrared photometry and spectrum simultaneously with spectral energy distribution (SED) models of parametric and nonparametric star formation histories (SFHs). Both models fit the observed SED well and confirm that this object is a massive quiescent galaxy with a stellar mass of
log
(
M
⋆
/
M
⊙
)
=
11.26
−
0.04
+
0.03
and
11.54
−
0.00
+
0.03
, and a star formation rate of SFR/
M
⊙
yr
−1
< 0.3 and
=
0.01
−
0.01
+
0.03
for parametric and nonparametric models, respectively. The SFH from the former modeling is described as an instantaneous starburst whereas that of the latter modeling is longer-lived, but both models agree with a sudden quenching of the star formation at ∼0.6 Gyr ago. This massive quiescent galaxy is confirmed in an extremely dense group of galaxies predicted as a progenitor of a brightest cluster galaxy formed via multiple mergers in cosmological numerical simulations. We discover three new plausible O
iii
λ
5007 emitters at 3.0791 ≤
z
spec
≤ 3.0833 serendipitously detected around the target. Two of them just between the target and its nearest massive galaxy are possible evidence of their interactions. They suggest the future great size and stellar mass evolution of this massive quiescent galaxy via mergers.
The physical properties and elemental abundances of the interstellar medium in galaxies during cosmic reionization are important for understanding the role of galaxies in this process. We report the ...Atacama Large Millimeter/submillimeter Array detection of an oxygen emission line at a wavelength of 88 micrometers from a galaxy at an epoch about 700 million years after the Big Bang. The oxygen abundance of this galaxy is estimated at about one-tenth that of the Sun. The nondetection of far-infrared continuum emission indicates a deficiency of interstellar dust in the galaxy. A carbon emission line at a wavelength of 158 micrometers is also not detected, implying an unusually small amount of neutral gas. These properties might allow ionizing photons to escape into the intergalactic medium.
ABSTRACT Recent observations with the Atacama Large Millimeter/submillimeter Array (ALMA) detected far-infrared emission lines such as the O iii $88\,\mu \mathrm{ m}$ line from galaxies at z ∼ 7−9. ...We use a cosmological simulation of galaxy formation to study the physical properties of O iii $88\,\mu \mathrm{ m}$ emitters. In a comoving volume of 50 h−1 Mpc on a side, we locate 34 galaxies with stellar masses greater than $10^8\ \rm M_{\odot }$ at z = 9, and more than 270 such galaxies at z = 7. We calculate the O iii $88\,\mu \mathrm{ m}$ luminosities ($L_{{\rm O\,{{\rm {\small{III}}}, 88}}}$) by combining a physical model of H ii regions with emission line calculations using the photoionization code cloudy. We show that the resulting $L_{{\rm O\,{{\rm {\small{III}}}, 88}}}$, for a given star formation rate, is slightly higher than predicted from the empirical relation for local galaxies, and is consistent with recent observations of galaxies at redshifts 7–9. Bright O iii emitters with $L_{{\rm O\,{{\rm {\small{III}}}, 88}}}\gt 10^8\, \rm L_{\odot }$ have star formation rates higher than $3\,\rm M_{\odot }\,{\rm yr}^{-1}$, and the typical metallicity is ${\sim } 0.1\, \rm Z_{\odot }$. The galaxies are hosted by dark matter haloes with masses greater than $10^{11}\, \rm M_{\odot }$. We propose to use the O iii 5007 Å line, to be detected by James Webb Space Telescope, to study the properties of galaxies whose O iii $88\,\mu \mathrm{ m}$ line emission has been already detected with ALMA.
FOREVER22: galaxy formation in protocluster regions Yajima, Hidenobu; Abe, Makito; Khochfar, Sadegh ...
Monthly Notices of the Royal Astronomical Society,
01/2022, Letnik:
509, Številka:
3
Journal Article
Recenzirano
Odprti dostop
ABSTRACT
We present results from a new cosmological hydrodynamics simulation campaign of protocluster (PC) regions, FOREVER22: FORmation and EVolution of galaxies in Extremely overdense Regions ...motivated by SSA22. The simulations cover a wide range of cosmological scales using three different zoom set-ups in a parent volume of $(714.2~\rm cMpc)^{3}$: PCR (Proto-Cluster Region; V = (28.6 cMpc)3, SPH particle mass, mSPH = 4.1 × 106 M⊙, and final redshift, zend = 2.0), BCG (Brightest proto-Cluster Galaxy; V ∼ (10 cMpc)3, mSPH = 5.0 × 105 M⊙ and zend = 4.0), and First (V ∼ (3 cMpc)3, mSPH = 7.9 × 103 M⊙ and zend = 9.5) runs, that allow us to focus on different aspects of galaxy formation. In the PCR runs, we follow 10 PCs, each harbouring 1–4 SMBHs with ${\rm M_{\rm BH}}\ge 10^{9}~{\rm M_{\odot }}$. One of the PC cores shows a spatially close arrangement of seven starburst galaxies with ${\rm SFR} \gtrsim 100~{\rm {\rm M_{\odot }}~{\rm yr^{-1}}}$ each, that are dust-obscured and would appear as submillimetre galaxies with flux ≳1 mJy at $1.1~ \rm mm$ in observations. The BCG runs show that the total SFRs of haloes hosting BCGs are affected by AGN feedback, but exceed $1000~{\rm {\rm M_{\odot }}~{\rm yr^{-1}}}$ at z ≲ 6. The First runs resolve mini-haloes hosting population (Pop) III stars and we show that, in PC regions, the dominant stellar population changes from Pop III to Pop II at z ≳ 20, and the first galaxies with ${\rm SFR} \gtrsim 18~{\rm {\rm M_{\odot }}~{\rm yr^{-1}}}$ form at z ∼ 10. These can be prime targets for future observations with the James Webb Space Telescope. Our simulations successfully reproduce the global star formation activities in observed PCs and suggest that PCs can kickstart cosmic reionization.
The number of centers with established adrenal venous sampling (AVS) programs for the subtype diagnosis of primary aldosteronism (PA) is limited.
Aim was to develop an algorithm for AVS based on ...subtype prediction by computed tomography (CT) and serum potassium.
A multi-institutional retrospective cohort study in Japan.
A total of 1591 patients with PA were classified into four groups according to CT findings and potassium status. Subtype diagnosis of PA was determined by AVS.
Prediction value of the combination of CT findings and potassium status for subtype diagnosis.
The percentages of unilateral hyperaldosteronism on AVS were higher in patients with unilateral disease on CT than those with bilateral normal results on CT (50.8% vs 14.6%, P < 0.01), and these percentages were higher in those with hypokalemia than those with normokalemia (58.4% vs 11.5%, P < 0.01). The prevalence and odds ratio for unilateral hyperaldosteronism on AVS were as follows: bilateral normal on CT with normokalemia, 6.2% (reference); unilateral disease on CT with normokalemia, 23.8% and 4.8 95% confidence interval (CI), 3.1 to 7.2; bilateral normal on CT with hypokalemia, 38.1% and 9.4 (95% CI, 6.2 to 14.1), and unilateral disease on CT with hypokalemia, 70.6% and 36.4 (95% CI, 24.7 to 53.5).
Patients with PA with bilateral normal results on CT and normokalemia likely have a low prior probability of a lateralized form of AVS and could be treated medically, whereas those with unilateral disease on CT and hypokalemia have a high probability of a lateralized form of AVS.
We present results from a deep 2′ × 3′ (comoving scale of 3.7 Mpc × 5.5 Mpc at z = 3) survey at 1.1 mm, taken with the Atacama Large Millimeter/submillimeter Array (ALMA) in the SSA22 field. We ...observe the core region of a z = 3.09 protocluster, achieving a typical rms sensitivity of 60 Jy beam−1 at a spatial resolution of 0 7. We detect 18 robust ALMA sources at a signal-to-noise ratio (S/N) > 5. Comparison between the ALMA map and a 1.1 mm map, taken with the AzTEC camera on the Atacama Submillimeter Telescope Experiment (ASTE), indicates that three submillimeter sources discovered by the AzTEC/ASTE survey are resolved into eight individual submillimeter galaxies (SMGs) by ALMA. At least 10 of our 18 ALMA SMGs have spectroscopic redshifts of z 3.09, placing them in the protocluster. This shows that a number of dusty starburst galaxies are forming simultaneously in the core of the protocluster. The nine brightest ALMA SMGs with S/N > 10 have a median intrinsic angular size of ( physical kpc at z = 3.09), which is consistent with previous size measurements of SMGs in other fields. As expected, the source counts show a possible excess compared to the counts in the general fields at S1.1mm ≥ 1.0 mJy, due to the protocluster. Our contiguous mm mapping highlights the importance of large-scale structures on the formation of dusty starburst galaxies.
We present the results from Atacama Large Millimeter/submillimeter Array observations of N ii 205 m, C ii 158 m, and O iii 88 m lines in an unlensed submillimeter galaxy at z = 4.3, COSMOS-AzTEC-1, ...hosting a compact starburst core with an effective radius of ∼1 kpc. The C ii and N ii emission are spatially resolved in 0 3-resolution (1 kpc in radius). The kinematic properties of the N ii emission are consistent with those of the CO(4-3) and C ii emission, suggesting that the ionized gas feels the same gravitational potential as the associated molecular gas and photodissociation regions (PDRs). On the other hand, the spatial extent is different among the lines and dust continuum: the C ii emitting gas is the most extended and the dust is the most compact, leading to a difference of the physical conditions in the interstellar medium. We derive the incident far-ultraviolet flux and the hydrogen gas density through PDR modeling by properly subtracting the contribution of ionized gas to the total C ii emission. The observed C ii emission is likely produced by dense PDRs with cm−3 and G0 = 103.5-3.75 in the central 1 kpc region and cm−3 and G0 = 103.25-3.5 in the central 3 kpc region. We have also successfully measured the line ratio of O iii/N ii in the central 3 kpc region of COSMOS-AzTEC-1 at z = 4.3, which is the highest redshift where both nitrogen and oxygen lines are detected. Under the most likely physical conditions, the measured luminosity ratio of LO iii/LN ii = 6.4 2.2 indicates a near solar metallicity with Zgas = 0.7-1.0 Z , suggesting a chemically evolved system at z = 4.3.
We present the largest to date sample of hydrogen Lyman continuum (LyC) emitting galaxy candidates at any redshift, with 18 Lyman alpha emitters (LAEs) and seven Lyman break galaxies (LBGs), obtained ...from the SSA22 field with Subaru/Suprime-Cam. The sample is based on the 159 LAEs and 136 LBGs observed in the field, all with spectroscopically confirmed redshifts, and these LyC candidates are selected as galaxies with counterparts in a narrow-band filter image which traces LyC at z greater than or equal to 3.06. Many LyC candidates show a spatial offset between the rest-frame non-ionizing ultraviolet (UV) detection and the LyC-emitting substructure or between the Ly alpha emission and LyC. The possibility of foreground contamination complicates the analysis of the nature of LyC emitters, although statistically it is highly unlikely that all candidates in our sample are contaminated by foreground sources. Many viable LyC LAE candidates have flux density ratios inconsistent with standard models, while also having too blue UV slopes to be foreground contaminants. Stacking reveals no significant LyC detection, suggesting that there is a dearth of objects with marginal LyC signal strength, perhaps due to a bimodality in the LyC emission. The foreground contamination corrected 3 sigma upper limits of the observed average flux density ratios are f sub( LyC)/f sub( UV) < 0.08 from stacking LAEs and f sub( LyC)/f sub( UV) < 0.02 from stacking LBGs. There is a sign of a positive correlation between LyC and Ly alpha , suggesting that both types of photons escape via a similar mechanism. The LyC detection rate among protocluster LBGs is seemingly lower compared to the field.
Abstract
We conduct a systematic search for galaxy protoclusters at z ∼ 3.8 based on the latest internal data release (S16A) of the Hyper Suprime-Cam Subaru strategic program (HSC-SSP). In the Wide ...layer of the HSC-SSP, we investigate the large-scale projected sky distribution of g-dropout galaxies over an area of 121 deg2, and identify 216 large-scale overdense regions (>4 σ overdensity significance) that are likely protocluster candidates. Of these, 37 are located within 8΄ (3.4 physical Mpc) of other protocluster candidates of higher overdensity, and are expected to merge into a single massive structure by z = 0. Therefore, we find 179 unique protocluster candidates in our survey. A cosmological simulation that includes projection effects predicts that more than 76% of these candidates will evolve into galaxy clusters with halo masses of at least 1014 M⊙ by z = 0. The unprecedented size of our protocluster candidate catalog allows us to perform, for the first time, an angular clustering analysis of the systematic sample of protocluster candidates. We find a correlation length of 35.0 h−1 Mpc. The relation between correlation length and number density of z ∼ 3.8 protocluster candidates is consistent with the prediction of the ΛCDM model, and the correlation length is similar to that of rich clusters in the local universe. This result suggests that our protocluster candidates are tracing similar spatial structures to those expected from the progenitors of rich clusters, and enhances the confidence that our method for identifying protoclusters at high redshifts is robust. In years to come, our protocluster search will be extended to the entire HSC-SSP Wide sky coverage of ∼ 1400 deg2 to probe cluster formation over a wide redshift range of z ∼ 2–6.
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