Abstract
We report the discovery of two companion sources to a strongly lensed galaxy SPT0418-47 (“ring”) at redshift 4.225, targeted by the JWST Early Release Science program. We confirm that these ...sources are at a similar redshift to the ring based on H
α
detected in the NIRSpec spectrum and C
ii
λ
158
μ
m line from the Atacama Large Millimeter/submillimeter Array (ALMA). Using multiple spectral lines detected in JWST/NIRSpec, the rest-frame optical to infrared images from NIRCam and MIRI and far-infrared dust continuum detected by ALMA, we argue that the newly discovered sources are actually lensed images of the same companion galaxy SPT0418-SE, hereafter referred to “SE,” located within 5 kpc in the source plane of the ring. The star formation rate derived using C
ii
and the dust continuum puts a lower limit of 17
M
☉
yr
−1
, while the SFR
H
α
is estimated to be >2 times lower, thereby confirming that SE is a dust-obscured star-forming galaxy. Analysis using optical strong line diagnostics suggests that SE has near-solar elemental abundance, while the ring appears to have supersolar metallicity O/H and N/O. We attempt to reconcile the high metallicity in this system by invoking early onset of star formation with continuous high star-forming efficiency or by suggesting that optical strong line diagnostics need revision at high redshift. We suggest that SPT0418-47 resides in a massive dark-matter halo with yet-to-be-discovered neighbors. This work highlights the importance of joint analysis of JWST and ALMA data for a deep and complete picture of the early universe.
We present a study of six far-infrared fine structure lines in the z = 4.225 lensed dusty star-forming galaxy SPT 0418−47 to probe the physical conditions of its interstellar medium (ISM). In ...particular, we report Atacama Pathfinder EXperiment (APEX) detections of the OI 145 μm and OIII 88 μm lines and Atacama Compact Array (ACA) detections of the NII 122 and 205 μm lines. The OI 145 μm/CII 158 μm line ratio is ∼5× higher compared to the average of local galaxies. We interpret this as evidence that the ISM is dominated by photo-dissociation regions with high gas densities. The line ratios, and in particular those of OIII 88 μm and NII 122 μm imply that the ISM in SPT 0418−47 is already chemically enriched to nearly solar metallicity. While the strong gravitational amplification was required to detect these lines with APEX, larger samples can be observed with the Atacama Large Millimeter/submillimeter Array (ALMA), and should allow observers to determine if the dense, solar metallicity ISM is common among these highly star-forming galaxies.
Full text
Available for:
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Abstract
The PASSAGES (Planck All-Sky Survey to Analyze Gravitationally-lensed Extreme Starbursts) collaboration has recently defined a sample of 30 gravitationally lensed dusty star-forming galaxies ...(DSFGs). These rare, submillimeter-selected objects enable high-resolution views of the most extreme sites of star formation in galaxies at cosmic noon. Here, we present the first major compilation of strong lensing analyses using
lenstool
for PASSAGES, including 15 objects spanning
z
= 1.1–3.3, using complementary information from 0.″6-resolution 1.1 mm Atacama Large Millimeter/submillimeter Array and 0.″4 5 cm Jansky Very Large Array continuum imaging, in tandem with 1.6
μ
m Hubble and optical imaging with Gemini-S. Magnifications range from
μ
= 2 to 28 (median
μ
= 7), yielding intrinsic infrared luminosities of
L
IR
= 0.2–5.9 × 10
13
L
⊙
(median 1.4 × 10
13
L
⊙
) and inferred star formation rates of 170–6300
M
⊙
yr
−1
(median 1500
M
⊙
yr
−1
). These results suggest that the PASSAGES objects comprise some of the most extreme known starbursts, rivaling the luminosities of even the brightest unlensed objects, further amplified by lensing. The intrinsic sizes of far-infrared continuum regions are large (
R
e
= 1.7–4.3 kpc; median 3.0 kpc) but consistent with
L
IR
–
R
e
scaling relations for
z
> 1 DSFGs, suggesting a widespread spatial distribution of star formation. With modestly high angular resolution, we explore if these objects might be maximal starbursts. Instead of approaching Eddington-limited surface densities, above which radiation pressure will disrupt further star formation, they are safely sub-Eddington—at least on global, galaxy-integrated scales.
We detect bright emission in the far-infrared (far-IR) fine structure O iii 88 m line from a strong lensing candidate galaxy, H-ATLAS J113526.3-014605, hereafter G12v2.43, at z = 3.127, using the ...second-generation Redshift (z) and Early Universe Spectrometer (ZEUS-2) at the Atacama Pathfinder Experiment Telescope (APEX). This is only the fifth detection of this far-IR line from a submillimeter galaxy at the epoch of galaxy assembly. The observed O iii luminosity of 7.1 × 109 L likely arises from H ii regions around massive stars, and the amount of Lyman continuum photons required to support the ionization indicate the presence of (1.2-5.2) × 106 equivalent O5.5 or higher stars, where would be the lensing magnification factor. The observed line luminosity also requires a minimum mass of ∼2 × 108 M in ionized gas, that is 0.33% of the estimated total molecular gas mass of 6 × 1010 M . We compile multi-band photometry tracing rest-frame ultraviolet to millimeter continuum emission to further constrain the properties of this dusty high-redshift, star-forming galaxy. Via SED modeling we find G12v2.43 is forming stars at a rate of 916 M yr−1 and already has a stellar mass of 8 × 1010 M . We also constrain the age of the current starburst to be Myr, making G12v2.43 a gas-rich galaxy lying above the star-forming main sequence at z ∼ 3, undergoing a growth spurt, and it could be on the main sequence within the derived gas depletion timescale of ∼66 Myr.
ABSTRACT
Hyperluminous infrared galaxies (HyLIRGs) are the most extreme star-forming systems observed in the early Universe, and their properties still elude comprehensive understanding. We have ...undertaken a large XMM–Newton observing programme to probe the total accreting black hole population in three HyLIRGs at z = 2.12, 3.25, and 3.55, gravitationally lensed by foreground galaxies. Selected from the Planck All-Sky Survey to Analyse Gravitationally lensed Extreme Starbursts (PASSAGES), these HyLIRGs have apparent infrared luminosities >1014 L⊙. Our observations revealed X-ray emission in each of them. PJ1336+49 appears to be dominated by high-mass X-ray binaries (HMXBs). Remarkably, the luminosity of this non-AGN X-ray emission exceeds by a factor of about 3 the value obtained by calibration with local galaxies with much lower star formation rates. This enhanced X-ray emission most likely highlights the efficacy of dynamical HMXB production within compact clusters, which is an important mode of star formation in HyLIRGs. The remaining two (PJ0116−24 and PJ1053+60) morphologically and spectrally exhibit a compact X-ray component in addition to the extended non-AGN X-ray emission, indicating the presence of Active Galactic Nuclei (AGNs). The AGN appears to be centrally located in the reconstructed source plane images of PJ0116−24, which manifests its star-forming activity predominantly within an extended galactic disc. In contrast, the AGN in the field of PJ1053+60 is projected 60 kpc away from the extreme star-forming galaxy and could be ejected from it. These results underline the synergistic potential of deep X-ray observations with strong lensing for the study of high-energy astrophysical phenomena in HyLIRGs.
A Fully Cryogenic Phased Array Camera for Radio Astronomy Cortes-Medellin, German; Vishwas, Amit; Parshley, Stephen C. ...
IEEE transactions on antennas and propagation,
2015-June, 2015-6-00, Volume:
63, Issue:
6
Journal Article
Peer reviewed
We have developed a fully cryogenically cooled phased array feed (PAF) prototype camera and tested it on the Arecibo Radio Telescope in the summer of 2013. The camera consists of 19 dual-polarized ...elements on a hexagonal grid. The array elements are modified sleeve dipoles specially designed to be reinsertable, to include a noise injection coupling port and to operate at 18 K. Experimental results for observations on the Arecibo Telescope demonstrate performance of the cryogenic amplifiers, digital beamforming, and sensitivity over the PAF field of view, and provide an important proof of concept for a full-scale PAF receiver.
Galaxies were surprisingly dusty in the early Universe, with more than half of the light emitted from stars being absorbed by dust within the system and re-radiated into far infrared (FIR, ...~50-150micron) wavelengths. Dusty star forming galaxies (DSFGs) dominate the co-moving star formation rate density of the Universe that peaks around redshift, z~2, making it compelling to study them in rest frame FIR bands. From galaxies at z>1, the FIR line emission from abundant ions like O++, C+ and N+, are redshifted into the short sub-mm telluric windows.My thesis work is based on upgrading and deploying the 2nd generation z (Redshift) and Early Universe Spectrometer (ZEUS-2), a long-slit, echelle grating spectrometer optimized to study broad (Δv = 300 km/s-1) spectral lines from galaxies in the 200-650 micron telluric windows using TES bolometers. These far-IR lines being extinction free and major coolants of the gas heated by (young) massive stars, are powerful probes of the physical conditions of the gas and the stellar radiation field.I present results from our observations of the OIII 88 micron line in galaxies at redshift, z~3-4, with ZEUS-2 at the Atacama Pathfinder Experiment (APEX) Telescope. To interpret our observations along with ancillary data from optical to radio facilities, we apply photoionization models for HII regions and Photo Dissociation Region (PDR) models and confirm that the galaxies host substantial ongoing obscured star formation. The presence of doubly ionized oxygen suggests hard radiation fields and often elevated ionization parameters that can only be accounted for by a population of massive stars formed during the ongoing starburst, that contribute a large fraction of the infrared luminosity. This work highlights the use of FIR line emission to trace the assembly of current day massive galaxies, details of their stellar populations and physical conditions of the interstellar medium undergoing rapid star-formation activity.
WISE J224607.6--052634.9 (W2246--0526) is a hot dust-obscured galaxy at $z$ = 4.601, and the most luminous obscured quasar known to date. W2246--0526 harbors a heavily obscured supermassive black ...hole that is most likely accreting above the Eddington limit. We present observations with the Atacama Large Millimeter/submillimeter Array (ALMA) in seven bands, including band 10, of the brightest far-infrared (FIR) fine-structure emission lines of this galaxy: OI m OIII m NII m OI m CII m NII m CI m $, and CI m $. A comparison of the data to a large grid of Cloudy radiative transfer models reveals that a high hydrogen density ($n_ H $) and extinction ($A_ V mag), together with extreme ionization ($log(U)=-0.5$) and a high X-ray to UV ratio ($ ox are required to reproduce the observed nuclear line ratios. The values of $ ox $ and $U$ are among the largest found in the literature and imply the existence of an X-ray-dominated region (XDR). In fact, this component explains the a priori very surprising non-detection of the OIII m $ emission line, which is actually suppressed, instead of boosted, in XDR environments. Interestingly, the best-fitted model implies higher X-ray emission and lower CO content than what is detected observationally, suggesting the presence of a molecular gas component that should be further obscuring the X-ray emission over larger spatial scales than the central region that is being modeled. These results highlight the need for multiline infrared observations to characterize the multiphase gas in high redshift quasars and, in particular, W2246--0526 serves as an extreme benchmark for comparisons of interstellar medium conditions with other quasar populations at cosmic noon and beyond.
Full text
Available for:
FMFMET, NUK, UL, UM, UPUK
We report the discovery of two companion sources to a strongly lensed galaxy
SPT0418-47 ("ring") at redshift 4.225, targeted by the JWST Early Release
Science program. We confirm that these sources ...are at a similar redshift as the
ring based on H$\alpha$ detected in the NIRSpec spectrum, and C II 158 $\mu$m
line from ALMA. Using multiple spectral lines detected in JWST/NIRSpec, the
rest-frame optical to infrared images from NIRCam and MIRI, and far-infrared
(FIR) dust continuum detected by ALMA, we argue that the newly discovered
sources are actually lensed images of the same companion galaxy, hereafter
referred to as SPT0418-SE ("SE"), located within 5 kpc in the source plane of
the ring. The star formation rate derived using C II and dust continuum puts
a lower limit of 17 M$_\odot$/yr, while the SFR$_\mathrm{H\alpha}$ is estimated
to be >2 times lower, thereby confirming that SE is a heavily dust obscured
star-forming galaxy. Analysis using optical strong line diagnostics suggests
that SE has near solar elemental abundance, while the ring appears to have
super-solar metallicity O/H and N/O. We attempt to reconcile the high
metallicity in this system by invoking early onset of star formation with
continuous high star forming efficiency, or that optical strong line
diagnostics need revision at high redshift. We suggest that SPT0418-47 resides
in a massive dark matter halo with yet to be discovered neighbors. This work
highlights the importance of joint analysis of JWST and ALMA data for a deep
and complete picture of the early Universe.
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![Detection of [O iii] at z ∼...](http://api.summon.serialssolutions.com/2.0.0/image/issn/XR4PS5YY4K/0004-637X/small "Detection of [O iii] at z ∼ 3: A Galaxy Above the Main Sequence, Rapidly Assembling Its Stellar Mass")
