scholarly journals GOODS-Herschel: Dust attenuation up to z∼4

2012 ◽  
Vol 8 (S292) ◽  
pp. 289-289 ◽  
Author(s):  
M. Pannella ◽  
D. Elbaz ◽  
E. Daddi

AbstractWe quantitatively explore in a unbiased way the evolution of dust attenuation up to z ≈ 4 as a function of galaxy properties. We have used one of the deepest datasets available at present, in the GOODS-N field, to select a star forming galaxy sample and robustly measure galaxy redshifts, star formation rates, stellar masses and UV restframe properties. Our main results can be summarized as follows: i) we confirm that galaxy stellar mass is a main driver of UV dust attenuation in star forming galaxies: more massive galaxies are more dust attenuated than less massive ones; ii) strikingly, we find that the correlation does not evolve with redshift: the amount of dust attenuation is the same at all cosmic epochs for a fixed stellar mass; iii) this finding explains why and how the SFR–AUV relation evolves with redshift: the same amount of star formation is less attenuated at higher redshift because it is hosted in less massive galaxies; iv) combining our finding with results from line emission surveys, we confirm that line reddening is larger than continuum reddening, at least up to z ≈ 1.5; v) given the redshift evolution of the mass-metallicity relation, we predict that star forming galaxies at a fixed metal content are more attenuated at high redshift. Finally, we explored the correlation between UV dust attenuation and the spectral slope: vi) the correlation is evolving with redshift with star forming galaxies at lower redshift having redder spectra than higher redshift ones for the same amount of dust attenuation.

2010 ◽  
Vol 6 (S277) ◽  
pp. 158-165
Author(s):  
Claudia Maraston

AbstractStellar populations carry information about the formation of galaxies and their evolution up to the present epoch. A wealth of observational data are available nowadays, which are analysed with stellar population models in order to obtain key properties such as ages, star formation histories, stellar masses. Differences in the models and/or in the assumptions regarding the star formation history affect the derived properties as much as differences in the data. I shall review the interpretation of high-redshift galaxy data from a model perspective. While data quality dominates galaxy analysis at the highest possible redshifts (z > 5), population modelling effects play the major part at lower redshifts. In particular, I discuss the cases of both star-forming galaxies at the peak of the cosmic star formation history as well as passive galaxies at redshift below 1 that are often used as cosmological probes. Remarks on the bridge between low and high-z massive galaxies conclude the contribution.


2016 ◽  
Vol 11 (S321) ◽  
pp. 273-273
Author(s):  
C. Catalán-Torrecilla ◽  
A. Gil de Paz ◽  
A. Castillo-Morales ◽  
J. Méndez-Abreu ◽  
S. Pascual ◽  
...  

AbstractExploring the spatial distribution of the star formation rate (SFR) in nearby galaxies is essential to understand their evolution through cosmic time. With this aim in mind, we use a representative sample that contains a variety of morphological types, the CALIFA Integral Field Spectroscopy (IFS) sample. Previous to this work, we have verified that our extinction-corrected Hα measurements successfully reproduce the values derived from other SFR tracers such as Hαobs + IR or UVobs + IR (Catalán-Torrecilla et al. 2015).Now, we go one step further applying 2-dimensional photometric decompositions (Méndez-Abreu et al. (2008), Méndez-Abreu et al. (2014)) over these datacubes. This method allows us to obtain the amount of SFR in the central part (bulge or nuclear source), the bar and the disk, separately. First, we determine the light coming from each component as the ratio between the luminosity in every component (bulge, bar or disk) and the total luminosity of the galaxy. Then, for each galaxy we multiply the IFS datacubes by these previous factors to recover the luminosity in each component. Finally, we derive the spectrum associated to each galaxy component integrating the spatial information in the weighted datacube using an elliptical aperture covering the whole galaxy.2D photometric decomposition applied over 3D datacubes will give us a more detailed understanding of the role that disks play in more massive galaxies. Knowing if the disks in more massive SF galaxies have on average a lower or higher level of star formation activity and how these results are affected by the presence of nuclear bars are still open questions that we can now solve. We describe the behavior of these components in the SFR vs. stellar mass diagram. In particular, we highlight the role of the disks and their contribution to both the integrated SFR for the whole galaxy and the SFR in the disk at different stellar masses in the SFR vs. stellar mass diagram together with their relative position to the star forming Main Sequence.


2016 ◽  
Vol 11 (S321) ◽  
pp. 327-329 ◽  
Author(s):  
Sandro Tacchella ◽  
C. Marcella Carollo ◽  
Avishai Dekel ◽  
Natascha Förster Schreiber ◽  
Alvio Renzini ◽  
...  

AbstractIn order to constrain – and understand – the growth of galaxies, we present a sample of ~ 30 galaxies at z ~ 2 with resolved distribution of stellar mass, star-formation rate, and dust attenuation on scales of ~ 1 kpc. We find that low- and intermediate-mass galaxies grow self-similarly, doubling their stellar mass in the centers and outskirts with the same pace. More massive galaxies (~ 1011 M⊙) have a reduced star-formation activity in their center: they grow mostly in the outskirts (inside-out quenching / formation). Similar trends are find in cosmological zoom-in simulations, highlighting that high stellar mass densities are formed in a gas-rich compaction phase. This nuclear ‘starburst’ phase is followed by a suppressed star-formation activity in the center, resulting in growth of the outskirts. All in all, we put forward that we witness at z ~ 2 the dissipative formation of z = 0 M* early-type galaxies.


2020 ◽  
Vol 492 (4) ◽  
pp. 4927-4944 ◽  
Author(s):  
M P Koprowski ◽  
K E K Coppin ◽  
J E Geach ◽  
U Dudzevičiūtė ◽  
Ian Smail ◽  
...  

ABSTRACT We analyse 870 $\mu$m Atacama Large Millimetre Array (ALMA) dust continuum detections of 41 canonically selected $z$ ≃ 3 Lyman-break galaxies (LBGs), as well as 209 ALMA-undetected LBGs, in follow-up of SCUBA-2 mapping of the UKIDSS Ultra Deep Survey (UDS) field. We find that our ALMA-bright LBGs lie significantly off the local IRX-beta relation and have relatively bluer rest-frame UV slopes (as parametrized by β), given their high values of the ‘infrared excess’ (IRX ≡ LIR/LUV), relative to the average ‘local’ IRX-β relation. We attribute this finding in part to the young ages of the underlying stellar populations but we find that the main reason behind the unusually blue UV slopes are the relatively shallow slopes of the corresponding dust attenuation curves. We show that, when stellar masses, M*, are being established via SED fitting, it is absolutely crucial to allow the attenuation curves to vary (rather than fixing it on Calzetti-like law), where we find that the inappropriate curves may underestimate the resulting stellar masses by a factor of ≃2–3× on average. In addition, we find these LBGs to have relatively high specific star-formation rates (sSFRs), dominated by the dust component, as quantified via the fraction of obscured star formation $(f_{\rm obs}\equiv {\rm SFR_{\rm IR}/{\rm SFR}_{\rm UV+IR}})$. We conclude that the ALMA-bright LBGs are, by selection, massive galaxies undergoing a burst of a star formation (large sSFRs, driven, for example, by secular or merger processes), with a likely geometrical disconnection of the dust and stars, responsible for producing shallow dust attenuation curves.


2020 ◽  
Vol 15 (S359) ◽  
pp. 22-26
Author(s):  
Carlos Gómez-Guijarro

AbstractStarbursting dust-rich galaxies are capable of assembling large amounts of stellar mass very quickly. They have been proposed as progenitors of the population of compact massive quiescent galaxies at z ˜ 2. To test this connection, we present a detailed spatially-resolved study of the stars, dust, and stellar mass in a sample of six submillimeter-bright starburst galaxies at z ˜ 4.5. We found that the systems are undergoing minor mergers and the bulk star formation is located in extremely compact regions. On the other hand, optically-compact star forming galaxies have also been proposed as immediate progenitors of compact massive quiescent galaxies. Were they formed in slow secular processes or in rapid merger-driven starbursts? We explored the location of galaxies with respect to star-forming and structural relations and study the burstiness of star formation. Our results suggest that compact star-forming galaxies could be starbursts winding down and eventually becoming quiescent.


2021 ◽  
Vol 163 (1) ◽  
pp. 28
Author(s):  
Yu-Zhong Wu

Abstract I assemble 4684 star-forming early-type galaxies (ETGs) and 2011 composite ETGs (located in the composite region on the BPT diagram) from the catalog of the Sloan Digital Sky Survey Data Release 7 MPA-JHU emission-line measurements. I compare the properties of both ETG samples and investigate their compositions, stellar masses, specific star formation rates (sSFRs), and excitation mechanisms. Compared with star-forming ETGs, composite ETGs have higher stellar mass and lower sSFR. In the stellar mass and u − r color diagram, more than 60% of star-forming ETGs and composite ETGs are located in the green valley, showing that the two ETG samples may have experienced star formation and that ∼17% of star-forming ETGs lie in the blue cloud, while ∼30% of composite ETGs lie in the red sequence. In the [N II]/Hα versus EWHα (the Hα equivalent width) diagram, all star-forming ETGs and most of the composite ETGs are located in the star-forming galaxy region, and composite ETGs have lower EWHα than their counterparts. We show the relations between 12+log(O/H) and log(N/O) for both ETG samples, and suggest that nitrogen production of some star-forming ETGs can be explained by the evolution scheme of Coziol et al., while the prodution of composite ETGs may be a consequence of the inflowing of metal-poor gas and these more evolved massive galaxies.


2020 ◽  
Vol 633 ◽  
pp. A105 ◽  
Author(s):  
Cheng Cheng ◽  
Cong Kevin Xu ◽  
Lizhi Xie ◽  
Zhizheng Pan ◽  
Wei Du ◽  
...  

Context. Most of the massive star-forming galaxies are found to have “inside-out” stellar mass growth modes, which means the inner parts of the galaxies mainly consist of the older stellar population, while the star forming in the outskirt of the galaxy is still ongoing. Aims. The high-resolution HST images from Hubble Deep UV Legacy Survey and Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey projects with the unprecedented depth in both F275W and F160W bands are the perfect data sets to study the forming and formed stellar distribution directly. Methods. We selected the low redshift (0.05 <  zspec <  0.3) galaxy sample from the GOODS-North field where the HST F275W and F160W images are available. Then we measured the half light radius in F275W and F160W bands, which are the indicators of the star formation and stellar mass. Results. By comparing the F275W and F160W half light radius, we find the massive galaxies are mainly follow the “inside-out” growth mode, which is consistent with the previous results. Moreover, the HST F275W and F160W images reveal that some of the low-mass galaxies (< 108 M⊙) have the “outside-in” growth mode: their images show a compact UV morphology, implying an ongoing star formation in the galaxy centre, while the stars in the outskirts of the galaxies are already formed. The two modes transit smoothly at stellar mass range about 108 − 9 M⊙ with a large scatter. We also try to identify the possible neighbour massive galaxies from the SDSS data, which represent the massive galaxy sample. We find that all of the spec-z selected galaxies have no massive galaxy nearby. Thus the “outside-in” mode we find in the low-mass galaxies are not likely originated from the environment.


2020 ◽  
Vol 493 (1) ◽  
pp. 141-160 ◽  
Author(s):  
S Santos ◽  
D Sobral ◽  
J Matthee ◽  
J Calhau ◽  
E da Cunha ◽  
...  

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.


2020 ◽  
Vol 492 (4) ◽  
pp. 5592-5606 ◽  
Author(s):  
A Katsianis ◽  
V Gonzalez ◽  
D Barrientos ◽  
X Yang ◽  
C D P Lagos ◽  
...  

ABSTRACT There is a severe tension between the observed star formation rate (SFR)–stellar mass (M⋆) relations reported by different authors at z = 1–4. In addition, the observations have not been successfully reproduced by state-of-the-art cosmological simulations that tend to predict a factor of 2–4 smaller SFRs at a fixed M⋆. We examine the evolution of the SFR–M⋆ relation of z = 1–4 galaxies using the skirt simulated spectral energy distributions of galaxies sampled from the Evolution and Assembly of GaLaxies and their Environments simulations. We derive SFRs and stellar masses by mimicking different observational techniques. We find that the tension between observed and simulated SFR–M⋆ relations is largely alleviated if similar methods are used to infer the galaxy properties. We find that relations relying on infrared wavelengths (e.g. 24 ${\rm \, \mu m}$, MIPS – 24, 70, and 160 ${\rm \, \mu m}$ or SPIRE – 250, 350, and 500 ${\rm \, \mu m}$) have SFRs that exceed the intrinsic relation by 0.5 dex. Relations that rely on the spectral energy distribution fitting technique underpredict the SFRs at a fixed stellar mass by −0.5 dex at z ∼ 4 but overpredict the measurements by 0.3 dex at z ∼ 1. Relations relying on dust-corrected rest-frame ultraviolet luminosities, are flatter since they overpredict/underpredict SFRs for low/high star-forming objects and yield deviations from the intrinsic relation from 0.10 to −0.13 dex at z ∼ 4. We suggest that the severe tension between different observational studies can be broadly explained by the fact that different groups employ different techniques to infer their SFRs.


2020 ◽  
Vol 15 (S359) ◽  
pp. 136-140
Author(s):  
Minju M. Lee ◽  
Ichi Tanaka ◽  
Rohei Kawabe

AbstractWe present studies of a protocluster at z =2.5, an overdense region found close to a radio galaxy, 4C 23.56, using ALMA. We observed 1.1 mm continuum, two CO lines (CO (4–3) and CO (3–2)) and the lower atomic carbon line transition ([CI](3P1-3P0)) at a few kpc (0″.3-0″.9) resolution. The primary targets are 25 star-forming galaxies selected as Hα emitters (HAEs) that are identified with a narrow band filter. These are massive galaxies with stellar masses of > 1010Mʘ that are mostly on the galaxy main sequence at z =2.5. We measure the molecular gas mass from the independent gas tracers of 1.1 mm, CO (3–2) and [CI], and investigate the gas kinematics of galaxies from CO (4–3). Molecular gas masses from the different measurements are consistent with each other for detection, with a gas fraction (fgas = Mgas/(Mgas+ Mstar)) of ≃ 0.5 on average but with a caveat. On the other hand, the CO line widths of the protocluster galaxies are typically broader by ˜50% compared to field galaxies, which can be attributed to more frequent, unresolved gas-rich mergers and/or smaller sizes than field galaxies, supported by our high-resolution images and a kinematic model fit of one of the galaxies. We discuss the expected scenario of galaxy evolution in protoclusters at high redshift but future large surveys are needed to get a more general view.


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