scholarly journals Using ALMA to resolve the nature of the early star-forming large-scale structure PLCK G073.4−57.5

2019 ◽  
Vol 625 ◽  
pp. A96 ◽  
Author(s):  
Rüdiger Kneissl ◽  
Maria del Carmen Polletta ◽  
Clement Martinache ◽  
Ryley Hill ◽  
Benjamin Clarenc ◽  
...  
Keyword(s):  
Star Formation ◽  
Galaxy Clusters ◽  
Large Scale ◽  
Near Infrared ◽  
High Redshift ◽  
Photometric Redshifts ◽  
Star Forming ◽  
Multi Wavelength ◽  
The Individual ◽  
Stellar Masses

Galaxy clusters at high redshift are key targets for understanding matter assembly in the early Universe, yet they are challenging to locate. A sample of more than 2000 high-z candidate structures has been found using Planck’s all-sky submillimetre maps, and a sub-set of 234 have been followed up with Herschel-SPIRE, which showed that the emission can be attributed to large overdensities of dusty star-forming galaxies. As a next step, we need to resolve and characterise the individual galaxies giving rise to the emission seen by Planck and Herschel, and to find out whether they constitute the progenitors of present-day, massive galaxy clusters. Thus, we targeted the eight brightest Herschel-SPIRE sources in the centre of the Planck peak PLCK G073.4−57.5 using ALMA at 1.3 mm, and complemented these observations with multi-wavelength data from Spitzer-IRAC, CFHT-WIRCam in the J and Ks bands, and JCMT’s SCUBA-2 instrument. We detected a total of 18 millimetre galaxies brighter than 0.3 mJy within the 2.4 arcmin2 ALMA pointings, corresponding to an ALMA source density 8–30 times higher than average background estimates and larger than seen in typical “proto-cluster” fields. We were able to match all but one of the ALMA sources to a near infrared (NIR) counterpart. The four most significant SCUBA-2 sources are not included in the ALMA pointings, but we find an 8σ stacking detection of the ALMA sources in the SCUBA-2 map at 850 μm. We derive photometric redshifts, infrared (IR) luminosities, star-formation rates (SFRs), stellar masses (ℳ), dust temperatures, and dust masses for all of the ALMA galaxies. Photometric redshifts identify two groups each of five sources, concentrated around z  ≃  1.5 and 2.4. The two groups show two “red sequences”, that is similar near-IR [3.6]  −  [4.5] colours and different J  −  Ks colours. The majority of the ALMA-detected galaxies are on the SFR versus ℳ main sequence (MS), and half of the sample is more massive than the characteristic ℳ* at the corresponding redshift. We find that the z  ≃  1.5 group has total SFR = 840−100+120 M⊙ yr−1 and ℳ = 5.8−2.4+1.7 × 1011 M⊙, and that the z  ≃  2.4 group has SFR = 1020−170+310 M⊙ yr−1 and ℳ = 4.2−2.1+1.5 × 1011 M⊙, but the latter group is more scattered in stellar mass and around the MS. Serendipitous CO line detections in two of the galaxies appear to match their photometric redshifts at z  =  1.54. We performed an analysis of star-formation efficiencies (SFEs) and CO- and mm-continuum-derived gas fractions of our ALMA sources, combined with a sample of 1 <  z <  3 cluster and proto-cluster members, and observed trends in both quantities with respect to stellar masses and in comparison to field galaxies.

scholarly journals Simulating JWST deep extragalactic imaging surveys and physical parameter recovery

2020 ◽  
Vol 640 ◽  
pp. A67
Author(s):  
O. B. Kauffmann ◽  
O. Le Fèvre ◽  
O. Ilbert ◽  
J. Chevallard ◽  
C. C. Williams ◽  
...  
Keyword(s):  
Star Formation ◽  
Near Infrared ◽  
High Redshift ◽  
Spectral Energy Distribution ◽  
Formation Rate ◽  
Spectral Energy ◽  
Photometric Redshifts ◽  
The Galaxy ◽  
Stellar Masses ◽  
The Impact

We present a new prospective analysis of deep multi-band imaging with the James Webb Space Telescope (JWST). In this work, we investigate the recovery of high-redshift 5 <  z <  12 galaxies through extensive image simulations of accepted JWST programs, including the Early Release Science in the EGS field and the Guaranteed Time Observations in the HUDF. We introduced complete samples of ∼300 000 galaxies with stellar masses of log(M*/M⊙) > 6 and redshifts of 0 <  z <  15, as well as galactic stars, into realistic mock NIRCam, MIRI, and HST images to properly describe the impact of source blending. We extracted the photometry of the detected sources, as in real images, and estimated the physical properties of galaxies through spectral energy distribution fitting. We find that the photometric redshifts are primarily limited by the availability of blue-band and near-infrared medium-band imaging. The stellar masses and star formation rates are recovered within 0.25 and 0.3 dex, respectively, for galaxies with accurate photometric redshifts. Brown dwarfs contaminating the z >  5 galaxy samples can be reduced to < 0.01 arcmin−2 with a limited impact on galaxy completeness. We investigate multiple high-redshift galaxy selection techniques and find that the best compromise between completeness and purity at 5 <  z <  10 using the full redshift posterior probability distributions. In the EGS field, the galaxy completeness remains higher than 50% at magnitudes mUV <  27.5 and at all redshifts, and the purity is maintained above 80 and 60% at z ≤ 7 and 10, respectively. The faint-end slope of the galaxy UV luminosity function is recovered with a precision of 0.1–0.25, and the cosmic star formation rate density within 0.1 dex. We argue in favor of additional observing programs covering larger areas to better constrain the bright end.

scholarly journals More connected, more active: galaxy clusters and groups at z ∼ 1 and the connection between their quiescent galaxy fractions and large-scale environments

2019 ◽  
Vol 490 (1) ◽  
pp. 135-155 ◽  
Author(s):  
Seong-Kook Lee ◽  
Myungshin Im ◽  
Minhee Hyun ◽  
Bomi Park ◽  
Jae-Woo Kim ◽  
...  
Keyword(s):  
Star Formation ◽  
Galaxy Clusters ◽  
Large Scale ◽  
High Redshift ◽  
Galaxy Cluster ◽  
Spectroscopic Observation ◽  
Star Forming ◽  
Large Scale Structures ◽  
Photometric Redshift ◽  
Redshift Galaxy

ABSTRACT High-redshift galaxy clusters, unlike local counterparts, show diverse star formation activities. However, it is still unclear what keeps some of the high-redshift clusters active in star formation. To address this issue, we performed a multiobject spectroscopic observation of 226 high-redshift (0.8 < z < 1.3) galaxies in galaxy cluster candidates and the areas surrounding them. Our spectroscopic observation reveals six to eight clusters/groups at z ∼ 0.9 and z ∼ 1.3. The redshift measurements demonstrate the reliability of our photometric redshift measurements, which in turn gives credibility for using photometric redshift members for the analysis of large-scale structures (LSSs). Our investigation of the large-scale environment (∼10 Mpc) surrounding each galaxy cluster reveals LSSs – structures up to ∼10 Mpc scale – around many of, but not all, the confirmed overdensities and the cluster candidates. We investigate the correlation between quiescent galaxy fraction of galaxy overdensities and their surrounding LSSs, with a larger sample of ∼20 overdensities including photometrically selected overdensities at 0.6 < z < 0.9. Interestingly, galaxy overdensities embedded within these extended LSSs show a lower fraction of quiescent galaxies ($\sim 20{{\ \rm per\ cent}}$) than isolated ones at similar redshifts (with a quiescent galaxy fraction of $\sim 50 {{\ \rm per\ cent}}$). Furthermore, we find a possible indication that clusters/groups with a high quiescent galaxy fraction are more centrally concentrated. Based on these results, we suggest that LSSs are the main reservoirs of gas and star-forming galaxies to keep galaxy clusters fresh and extended in size at z ∼ 1.

scholarly journals The evolution of rest-frame UV properties, Ly α EWs, and the SFR–stellar mass relation at z ∼ 2–6 for SC4K LAEs

2020 ◽  
Vol 493 (1) ◽  
pp. 141-160 ◽  
Author(s):  
S Santos ◽  
D Sobral ◽  
J Matthee ◽  
J Calhau ◽  
E da Cunha ◽  
...  
Keyword(s):  
Star Formation ◽  
Rest Frame ◽  
High Redshift ◽  
Cosmic Time ◽  
Stellar Mass ◽  
Spectral Energy ◽  
Mass Relation ◽  
Star Forming ◽  
The Individual ◽  
Stellar Masses

ABSTRACT We explore deep rest-frame UV to FIR data in the COSMOS field to measure the individual spectral energy distributions (SED) of the ∼4000 SC4K (Sobral et al.) Lyman α (Ly α) emitters (LAEs) at z ∼ 2–6. We find typical stellar masses of 109.3 ± 0.6 M⊙ and star formation rates (SFR) of SFR$_{\rm SED}=4.4^{+10.5}_{-2.4}$ M⊙ yr−1 and SFR$_{\rm Ly\,\alpha }=5.9^{+6.3}_{-2.6}$ M⊙ yr−1, combined with very blue UV slopes of $\beta =-2.1^{+0.5}_{-0.4}$, but with significant variations within the population. MUV and β are correlated in a similar way to UV-selected sources, but LAEs are consistently bluer. This suggests that LAEs are the youngest and/or most dust-poor subset of the UV-selected population. We also study the Ly α rest-frame equivalent width (EW0) and find 45 ‘extreme’ LAEs with EW0 &gt; 240 Å (3σ), implying a low number density of (7 ± 1) × 10−7 Mpc−3. Overall, we measure little to no evolution of the Ly α EW0 and scale length parameter (w0), which are consistently high (EW$_0=140^{+280}_{-70}$ Å, $w_0=129^{+11}_{-11}$ Å) from z ∼ 6 to z ∼ 2 and below. However, w0 is anticorrelated with MUV and stellar mass. Our results imply that sources selected as LAEs have a high Ly α escape fraction (fesc,Ly α) irrespective of cosmic time, but fesc,Ly α is still higher for UV-fainter and lower mass LAEs. The least massive LAEs (&lt;109.5 M⊙) are typically located above the star formation ‘main sequence’ (MS), but the offset from the MS decreases towards z ∼ 6 and towards 1010 M⊙. Our results imply a lack of evolution in the properties of LAEs across time and reveals the increasing overlap in properties of LAEs and UV-continuum selected galaxies as typical star-forming galaxies at high redshift effectively become LAEs.

scholarly journals Quenching of Star-formation Activity of High-redshift Galaxies in Clusters and Field

2015 ◽  
Vol 11 (S319) ◽  
pp. 28-28
Author(s):  
Seong-Kook Lee ◽  
Myungshin Im ◽  
Jae-Woo Kim ◽  
Jennifer Lotz ◽  
Conor McPartland ◽  
...  
Keyword(s):  
Star Formation ◽  
Near Infrared ◽  
High Redshift ◽  
Galaxy Cluster ◽  
Stellar Mass ◽  
High Mass ◽  
Photometric Redshifts ◽  
Redshift Range ◽  
Star Formation In Galaxies ◽  
Stellar Masses

AbstractAt local, galaxy properties are well known to be clearly different in different environments. However, it is still an open question how this environment-dependent trend has been shaped. We present the results of our investigation about the evolution of star-formation properties of galaxies over a wide redshift range, from z ~ 2 to z ~ 0.5, focusing its dependence on their stellar mass and environment (Lee et al. 2015). In the UKIDSS/UDS region, covering ~2800 square arcmin, we estimated photometric redshifts and stellar population properties, such as stellar masses and star-formation rates, using the deep optical and near-infrared data available in this field. Then, we identified galaxy cluster candidates within the given redshift range. Through the analysis and comparison of star-formation (SF) properties of galaxies in clusters and in field, we found interesting results regarding the evolution of SF properties of galaxies: (1) regardless of redshifts, stellar mass is a key parameter controlling quenching of star formation in galaxies; (2) At z < 1, environmental effects become important at quenching star formation regardless of stellar mass of galaxies; and (3) However, the result of the environmental quenching is prominent only for low mass galaxies (M* < 1010 M⊙) since the star formation in most of high mass galaxies are already quenched at z > 1.

scholarly journals Planck’s dusty GEMS

2018 ◽  
Vol 620 ◽  
pp. A60 ◽  
Author(s):  
R. Cañameras ◽  
N. P. H. Nesvadba ◽  
M. Limousin ◽  
H. Dole ◽  
R. Kneissl ◽  
...  
Keyword(s):  
Star Formation ◽  
Near Infrared ◽  
Infrared Imaging ◽  
High Redshift ◽  
Dust Emission ◽  
Galaxy Cluster ◽  
Star Forming ◽  
The Galaxy ◽  
Mass Outflow ◽  
Gas Accretion

We report the discovery of a molecular wind signature from a massive intensely star-forming clump of a few 109 M⊙, in the strongly gravitationally lensed submillimeter galaxy “the Emerald” (PLCK_G165.7+49.0) at z = 2.236. The Emerald is amongst the brightest high-redshift galaxies on the submillimeter sky, and was initially discovered with the Planck satellite. The system contains two magnificient structures with projected lengths of 28.5″ and 21″ formed by multiple, near-infrared arcs, falling behind a massive galaxy cluster at z = 0.35, as well as an adjacent filament that has so far escaped discovery in other wavebands. We used HST/WFC3 and CFHT optical and near-infrared imaging together with IRAM and SMA interferometry of the CO(4–3) line and 850 μm dust emission to characterize the foreground lensing mass distribution, construct a lens model with LENSTOOL, and calculate gravitational magnification factors between 20 and 50 in most of the source. The majority of the star formation takes place within two massive star-forming clumps which are marginally gravitationally bound and embedded in a 9 × 1010 M⊙, fragmented disk with 20% gas fraction. The stellar continuum morphology is much smoother and also well resolved perpendicular to the magnification axis. One of the clumps shows a pronounced blue wing in the CO(4–3) line profile, which we interpret as a wind signature. The mass outflow rates are high enough for us to suspect that the clump might become unbound within a few tens of Myr, unless the outflowing gas can be replenished by gas accretion from the surrounding disk. The velocity offset of –200 km s−1 is above the escape velocity of the clump, but not that of the galaxy overall, suggesting that much of this material might ultimately rain back onto the galaxy and contribute to fueling subsequent star formation.

scholarly journals Horizon-AGN virtual observatory – 1. SED-fitting performance and forecasts for future imaging surveys

2019 ◽  
Vol 486 (4) ◽  
pp. 5104-5123 ◽  
Author(s):  
C Laigle ◽  
I Davidzon ◽  
O Ilbert ◽  
J Devriendt ◽  
D Kashino ◽  
...  
Keyword(s):  
Star Formation ◽  
Near Infrared ◽  
Star Formation History ◽  
Photometric Redshifts ◽  
Dark Energy Survey ◽  
Hydrodynamical Simulation ◽  
Formation History ◽  
Stellar Masses ◽  
Dust Attenuation ◽  
The Impact

Abstract Using the light-cone from the cosmological hydrodynamical simulation horizon-AGN, we produced a photometric catalogue over 0 &lt; z &lt; 4 with apparent magnitudes in COSMOS, Dark Energy Survey, Large Synoptic Survey Telescope (LSST)-like, and Euclid-like filters at depths comparable to these surveys. The virtual photometry accounts for the complex star formation history (SFH) and metal enrichment of horizon-AGN galaxies, and consistently includes magnitude errors, dust attenuation, and absorption by intergalactic medium. The COSMOS-like photometry is fitted in the same configuration as the COSMOS2015 catalogue. We then quantify random and systematic errors of photometric redshifts, stellar masses, and star formation rates (SFR). Photometric redshifts and redshift errors capture the same dependencies on magnitude and redshift as found in COSMOS2015, excluding the impact of source extraction. COSMOS-like stellar masses are well recovered with a dispersion typically lower than 0.1 dex. The simple SFHs and metallicities of the templates induce a systematic underestimation of stellar masses at z &lt; 1.5 by at most 0.12 dex. SFR estimates exhibit a dust-induced bimodality combined with a larger scatter (typically between 0.2 and 0.6 dex). We also use our mock catalogue to predict photometric redshifts and stellar masses in future imaging surveys. We stress that adding Euclid near-infrared photometry to the LSST-like baseline improves redshift accuracy especially at the faint end and decreases the outlier fraction by a factor ∼2. It also considerably improves stellar masses, reducing the scatter up to a factor 3. It would therefore be mutually beneficial for LSST and Euclid to work in synergy.

scholarly journals The Evolution of Luminous Compact Blue Galaxies: Disks or Spheroids?

2010 ◽  
Vol 6 (S277) ◽  
pp. 291-295
Author(s):  
D. J. Pisano ◽  
K. Rabidoux ◽  
C. A. Garland ◽  
R. Guzmán ◽  
F. J. Castander ◽  
...  
Keyword(s):  
Star Formation ◽  
High Redshift ◽  
High Surface ◽  
Blue Color ◽  
Dynamical Mass ◽  
Star Forming ◽  
Blue Galaxies ◽  
Multi Wavelength ◽  
Fisher Relation ◽  
Combined Data

AbstractLuminous compact blue galaxies (LCBGs) are a diverse class of galaxies characterized by high luminosity, blue color, and high surface brightness that sit at the critical juncture of galaxies evolving from the blue to the red sequence. As part of our multi-wavelength survey of local LCBGs, we have been studying the HI content of these galaxies using both single-dish telescopes and interferometers. Our goals are to determine if single-dish HI observations represent a true measure of the dynamical mass of LCBGs and to look for signatures of recent interactions that may be triggering star formation in LCBGs. Our data show that while some LCBGs are undergoing interactions, many appear isolated. While all LCBGs contain HI and show signatures of rotation, the population does not lie on the Tully-Fisher relation nor can it evolve onto it. Furthermore, the HI maps of many LCBGs show signatures of dynamically hot components, suggesting that we are seeing the formation of a thick disk or spheroid in at least some LCBGs. There is good agreement between the HI and Hα kinematics for LCBGs, and both are similar in appearance to the Hα kinematics of high redshift star-forming galaxies. Our combined data suggest that star formation in LCBGs is primarily quenched by virial heating, consistent with model predictions.

scholarly journals Molecular gas, stars, and dust in sub-L⋆ star-forming galaxies at z ~ 2: Evidence for universal star formation and non-universal dust-to-gas ratio

2015 ◽  
Vol 11 (S315) ◽  
pp. 254-257
Author(s):  
Miroslava Dessauges-Zavadsky ◽  
Michel Zamojski ◽  
Daniel Schaerer ◽  
Françoise Combes ◽  
Eiichi Egami ◽  
...  
Keyword(s):  
Star Formation ◽  
Gravitational Lensing ◽  
High Redshift ◽  
Clear Trend ◽  
Star Forming ◽  
Solar Metallicity ◽  
Stellar Masses ◽  
Formation Efficiency ◽  
Gas Ratio ◽  
Single Relation

AbstractCurrent star-forming galaxies (SFGs) with CO measurements at z ~ 2 suffer from a bias toward high star formation rates (SFR) and high stellar masses (M*). It is yet essential to extend the CO measurements to the more numerous z ~ 2 SFGs with LIR < L⋆ = 4× 1011 L⊙ and M* < 2.5× 1010 M⊙. We have achieved CO, stars, and dust measurements in 8 such sub-L⋆ SFGs with the help of gravitational lensing. Combined with CO-detected galaxies from the literature, we find that the LIR, L′CO(1−0) data are best-fitted with a single relation that favours a universal star formation. This picture emerges because of the enlarged star formation efficiency spread of the current z>1 SFGs sample. We show that this spread is mostly triggered by the combination of redshift, specific SFR, and M*. Finally, we find evidence for a non-universal dust-to-gas ratio (DGR) with a clear trend for a lower DGR mean in z>1 SFGs by a factor of 2 with respect to local galaxies and high-redshift sub-mm galaxies at fixed about solar metallicity.

scholarly journals Properties of ionized outflows in MaNGA DR2 galaxies

2019 ◽  
Vol 486 (1) ◽  
pp. 344-359 ◽  
Author(s):  
Bruno Rodríguez del Pino ◽  
Santiago Arribas ◽  
Javier Piqueras López ◽  
Montserrat Villar-Martín ◽  
Luis Colina
Keyword(s):  
Star Formation ◽  
Emission Region ◽  
Ionization Mechanism ◽  
Host Galaxies ◽  
Star Forming ◽  
Spatially Resolved ◽  
Nearby Galaxies ◽  
Nuclear Regions ◽  
The Individual ◽  
Stellar Masses

ABSTRACT We present the results from a systematic search and characterization of ionized outflows in nearby galaxies using the data from the second Data Release of the Mapping Nearby Galaxies at Arecibo Point Observatory (MaNGA) Survey (DR2; &gt;2700 galaxies, z ≤ 0.015). Using the spatially resolved spectral information provided by the MANGA data, we have identified ∼5200 H α-emitting regions across the galaxies and searched for signatures of ionized outflows. We find evidence for ionized outflows in 105 regions from 103 galaxies, roughly 7 per cent of all the H α-emitting galaxies identified in this work. Most of the outflows are nuclear, with only two cases detected in off-nuclear regions. Our analysis allows us to study ionized outflows in individual regions with star formation rates (SFRs) down to ∼0.01 M⊙ yr−1, extending the ranges probed by previous works. The kinematics of the outflowing gas is strongly linked to the type of ionization mechanism: regions characterized by low-ionization emission region emission (LIER) host the outflows with more extreme kinematics (FWHMbroad ∼ 900 km s−1), followed by those originated in active galactic nuclei (550 km s−1), ‘Intermediate’ (450 km s−1), and star-forming (350 km s−1) regions. Moreover, in most of the outflows we find evidence for gas ionized by shocks. We find a trend for higher outflow kinematics towards larger stellar masses of the host galaxies but no significant variation as a function of star formation properties within the SFR regime we probe (∼0.01–10 M⊙ yr−1). Our results also show that the fraction of outflowing gas that can escape from galaxies decreases towards higher dynamical masses, contributing to the preservation of the mass–metallicity relation by regulating the amount of metals in galaxies. Finally, assuming that the extensions of the outflows are significantly larger than the individual star-forming regions, as found in previous works, our results also support the presence of star formation within ionized outflows, as recently reported by Maiolino et al. (2017) and Gallagher et al. (2018).

Panchromatic study of the first galaxies in cosmological simulations

2019 ◽  
Vol 15 (S341) ◽  
pp. 240-244
Author(s):  
Hidenobu Yajima ◽  
Shohei Arata ◽  
Makito Abe ◽  
Kentaro Nagamine
Keyword(s):  
Star Formation ◽  
Initial Conditions ◽  
High Redshift ◽  
Radiative Properties ◽  
Massive Galaxies ◽  
Star Forming ◽  
Lyman Alpha ◽  
Radiation Properties ◽  
Multi Wavelength ◽  
First Galaxies

AbstractRecent discoveries of high-redshift galaxies have revealed the diversity of their physical properties, from normal star-forming galaxies to starburst galaxies. To understand the properties of these observed galaxies, it is crucial to understand the star formation (SF) history, and the radiation properties associated with the SF activity. Here we present the results of cosmological hydrodynamic simulations with zoom-in initial conditions, and show the formation of the first galaxies and their evolution towards observable galaxies at z = 6. In addition, we show their multi-wavelength radiative properties. We find that star formation occurs intermittently due to supernova (SN) feedback at z > 10, and their radiation properties rapidly change with time. We suggest that the first galaxies are bright at UV wavelengths just after the starburst phase, and become extended Lyman-alpha sources. We also show that massive galaxies cause dusty starburst and become bright at infrared wavelengths.

Sign in / Sign up

Export Citation Format

Share Document