We present a survey of the C ii 158 m line and underlying far-infrared (FIR) dust continuum emission in a sample of 27 quasars using the Atacama Large Millimeter Array (ALMA) at resolution. The C ii ...line was significantly detected (at - ) in 23 sources (85%). We find typical line luminosities of , and an average line width of ∼385 . The C ii-to-far-infrared luminosity ratios (C ii/FIR) in our sources span one order of magnitude, highlighting a variety of conditions in the star-forming medium. Four quasar host galaxies are clearly resolved in their C ii emission on a few kpc scales. Basic estimates of the dynamical masses of the host galaxies give masses between 2 × 1010 and 2 × 1011 , i.e., more than an order of magnitude below what is expected from local scaling relations, given the available limits on the masses of the central black holes ( , assuming Eddington-limited accretion). In stacked ALMA C ii spectra of individual sources in our sample, we find no evidence of a deviation from a single Gaussian profile. The quasar luminosity does not strongly correlate with either the C ii luminosity or equivalent width. This survey (with typical on-source integration times of 8 minutes) showcases the unparalleled sensitivity of ALMA at millimeter wavelengths, and offers a unique reference sample for the study of the first massive galaxies in the universe.
A Simplified, Lossless Reanalysis of PAPER-64 Kolopanis, Matthew; Jacobs, Daniel C.; Cheng, Carina ...
Astrophysical journal/The Astrophysical journal,
10/2019, Volume:
883, Issue:
2
Journal Article
Peer reviewed
Open access
We present limits on the 21 cm power spectrum from the Epoch of Reionization using data from the 64 antenna configuration of the Donald C. Backer Precision Array for Probing the Epoch of Reionization ...(PAPER) analyzed through a power spectrum pipeline independent from previous PAPER analyses. Previously reported results from PAPER have been found to contain significant signal loss. Several lossy steps from previous PAPER pipelines have not been included in this analysis, namely delay-based foreground filtering, optimal fringe-rate filtering, and empirical covariance-based estimators. Steps that remain in common with previous analyses include redundant calibration and local sidereal time (LST) binning. The power spectra reported here are effectively the result of applying a linear Fourier transform analysis to the calibrated, LST-binned data. This analysis also uses more data than previous publications, including the complete available redshift range of z ∼ 7.5 to 11. In previous PAPER analyses, many power spectrum measurements were found to be detections of noncosmological power at levels of significance ranging from two to hundreds of times the theoretical noise. Here, excess power is examined using redundancy between baselines and power spectrum jackknives. The upper limits we find on the 21 cm power spectrum from reionization are , , , , , and at redshifts z = 10.87, 9.93, 8.68, 8.37, 8.13, and 7.48, respectively. For reasons described in Cheng et al., these limits supersede all previous PAPER results.
ABSTRACT We report new IRAM/PdBI, JCMT/SCUBA-2, and VLA observations of the ultraluminous quasar SDSS J010013.02+280225.8 (hereafter, J0100+2802) at z = 6.3, which hosts the most massive supermassive ...black hole (SMBH), , that is known at z > 6. We detect the C ii 158 m fine structure line and molecular CO(6-5) line and continuum emission at 353, 260, and 3 GHz from this quasar. The CO(2-1) line and the underlying continuum at 32 GHz are also marginally detected. The C ii and CO detections suggest active star formation and highly excited molecular gas in the quasar host galaxy. The redshift determined with the C ii and CO lines shows a velocity offset of from that measured with the quasar Mg ii line. The CO (2-1) line luminosity provides a direct constraint on the molecular gas mass, which is about . We estimate the FIR luminosity to be , and the UV-to-FIR spectral energy distribution of J0100+2802 is consistent with the templates of the local optically luminous quasars. The derived C ii-to-FIR luminosity ratio of J0100+2802 is 0.0010 0.0002, which is slightly higher than the values of the most FIR luminous quasars at z ∼ 6. We investigate the constraint on the host galaxy dynamical mass of J0100+2802 based on the C ii line spectrum. It is likely that this ultraluminous quasar lies above the local SMBH-galaxy mass relationship, unless we are viewing the system at a small inclination angle.
We present a characterization of the physical properties of a sample of 35 securely detected, dusty galaxies in the deep ALMA 1.2 mm image obtained as part of the ALMA Spectroscopic Survey in the ...Hubble Ultra Deep Field (ASPECS) Large Program. This sample is complemented by 26 additional sources identified via an optical/infrared source positional prior. Using their well-characterized spectral energy distributions, we derive median stellar masses and star formation rates (SFR) of and 30 M☉ yr−1, respectively, and interquartile ranges of (2.4-11.7) × 1010 M☉ and 20-50 M☉ yr−1. We derive a median spectroscopic redshift of 1.8 with an interquartile range 1.1-2.6, significantly lower than submillimeter galaxies detected in shallower, wide-field surveys. We find that 59% 13%, 6% 4%, and 34% 9% of our sources are within, above, and below 0.4 dex from the SFR-stellar-mass relation or main sequence (MS), respectively. The ASPECS galaxies closely follow the SFR-molecular gas mass relation and other previously established scaling relations, confirming a factor of five increase of the gas-to-stellar-mass ratio from z = 0.5 to 2.5 and a mild evolution of the gas depletion timescales with a typical value of 0.7 Gyr at z = 1-3. ASPECS galaxies located significantly below the MS, a poorly exploited parameter space, have low gas-to-stellar-mass ratios of ∼0.1-0.2 and long depletion timescales >1 Gyr. Galaxies along the MS dominate the cosmic density of molecular gas at all redshifts. Systems above the MS have an increasing contribution to the total gas reservoirs from z < 1 to z = 2.5, while the opposite is found for galaxies below the MS.
We present a study of the C ii 158 m line and underlying far-infrared (FIR) continuum emission of 27 quasar host galaxies at z ∼ 6, traced by the Atacama Large Millimeter/submillimeter Array at a ...spatial resolution of ∼1 physical kpc. The C ii emission in the bright, central regions of the quasars have sizes of 1.0-4.8 kpc. The dust continuum emission is typically more compact than C ii. We find that 13/27 quasars (approximately one-half) have companion galaxies in the field, at projected separations of 3-90 kpc. The position of dust emission and the Gaia-corrected positions of the central accreting black holes are cospatial (typical offsets 0 1). This suggests that the central black holes are located at the bottom of the gravitational wells of the dark matter halos in which the quasar hosts reside. Some outliers with offsets of ∼500 pc can be linked to disturbed morphologies, most likely due to ongoing or recent mergers. We find no correlation between the central brightness of the FIR emission and the bolometric luminosity of the accreting black hole. The FIR-derived star formation rate densities (SFRDs) in the host galaxies peak at the galaxies' centers, at typical values between 100 and 1000 M yr−1 kpc−2. These values are below the Eddington limit for star formation, but similar to those found in local ultraluminous infrared galaxies. The SFRDs drop toward larger radii by an order of magnitude. Likewise, the C ii/FIR luminosity ratios of the quasar hosts are lowest in their centers (few ×10−4) and increase by a factor of a few toward the galaxies' outskirts, consistent with resolved studies of lower-redshift sources.
Abstract Using the Karl G. Jansky Very Large Array, we have detected absorption lines due to carbon monoxide, CO( J = 0 → 1), and the cyano radical, CN( N = 0 → 1), associated with radio galaxy B2 ...0902+34 at redshift z = 3.4. The detection of millimeter-band absorption observed 1.5 Gyr after the Big Bang facilitates studying molecular clouds down to gas masses inaccessible to emission-line observations. The CO absorption in B2 0902+34 has a peak optical depth of τ ≥ 8.6% and consists of two components, one of which has the same redshift as previously detected 21 cm absorption of neutral hydrogen (H i ) gas. Each CO component traces an integrated H 2 column density of N H 2 ≳ 3 × 10 20 cm −2 . CN absorption is detected for both CO components, as well as for a blueshifted component not detected in CO, with CO/CN line ratios ranging from ≲0.4 to 2.4. We discuss the scenario that the absorption components originate from collections of small and dense molecular clouds that are embedded in a region with more diffuse gas and high turbulence, possibly within the influence of the central active galactic nucleus or a starburst region. The degree of reddening in B2 0902+34, with rest-frame color B − K ∼ 4.2, is lower than the very red colors ( B − K > 6) found among other known redshifted CO absorption systems at z < 1. Nevertheless, when including the many nondetections from the literature, a potential correlation between the absorption-line strength and B − K color is evident, giving weight to the argument that the red colors of CO absorbers are due to a high dust content.
Gas surrounding high-redshift galaxies has been studied through observations of absorption line systems toward background quasars for decades. However, it has proven difficult to identify and ...characterize the galaxies associated with these absorbers due to the intrinsic faintness of the galaxies compared with the quasars at optical wavelengths. Using the Atacama Large Millimeter/Submillimeter Array, we report on detections of C ii 158-μm line and dust-continuum emission from two galaxies associated with two such absorbers at a redshift of z ~ 4. Our results indicate that the hosts of these high-metallicity absorbers have physical properties similar to massive star-forming galaxies and are embedded in enriched neutral hydrogen gas reservoirs that extend well beyond the star-forming interstellar medium of these galaxies.
Full text
Available for:
BFBNIB, NMLJ, NUK, ODKLJ, PNG, SAZU, UL, UM, UPUK
Abstract
We make use of sensitive (9.3
μ
Jy beam
−1
rms) 1.2 mm continuum observations from the Atacama Large Millimeter/submillimeter Array (ALMA) Spectroscopic Survey in the Hubble Ultra-Deep Field ...(ASPECS) large program to probe dust-enshrouded star formation from 1362 Lyman-break galaxies spanning the redshift range
z
= 1.5–10 (to ∼7–28
M
⊙
yr
−1
at 4
σ
over the entire range). We find that the fraction of ALMA-detected galaxies in our
z
= 1.5–10 samples increases steeply with stellar mass, with the detection fraction rising from 0% at 10
9.0
M
⊙
to
% at >10
10
M
⊙
. Moreover, on stacking all 1253 low-mass (<10
9.25
M
⊙
) galaxies over the ASPECS footprint, we find a mean continuum flux of −0.1 ± 0.4
μ
Jy beam
−1
, implying a hard upper limit on the obscured star formation rate of <0.6
M
⊙
yr
−1
(4
σ
) in a typical low-mass galaxy. The correlation between the infrared excess (IRX) of UV-selected galaxies (
L
IR
/
L
UV
) and the UV-continuum slope is also seen in our ASPECS data and shows consistency with a Calzetti-like relation at >
and an SMC-like relation at lower masses. Using stellar mass and
β
measurements for
z
∼ 2 galaxies over the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey, we derive a new empirical relation between
β
and stellar mass and then use this correlation to show that our IRX–
β
and IRX–stellar mass relations are consistent with each other. We then use these constraints to express the IRX as a bivariate function of
β
and stellar mass. Finally, we present updated estimates of star formation rate density determinations at
z
> 3, leveraging present improvements in the measured IRX and recent probes of ultraluminous far-IR galaxies at
z
> 2.
The Epoch of Reionization (EoR) is an uncharted era in our universe's history during which the birth of the first stars and galaxies led to the ionization of neutral hydrogen in the intergalactic ...medium. There are many experiments investigating the EoR by tracing the 21 cm line of neutral hydrogen. Because this signal is very faint and difficult to isolate, it is crucial to develop analysis techniques that maximize sensitivity and suppress contaminants in data. It is also imperative to understand the trade-offs between different analysis methods and their effects on power spectrum estimates. Specifically, with a statistical power spectrum detection in HERA's foreseeable future, it has become increasingly important to understand how certain analysis choices can lead to the loss of the EoR signal. In this paper, we focus on signal loss associated with power spectrum estimation. We describe the origin of this loss using both toy models and data taken by the 64-element configuration of the Donald C. Backer Precision Array for Probing the Epoch of Reionization (PAPER). In particular, we highlight how detailed investigations of signal loss have led to a revised, higher 21 cm power spectrum upper limit from PAPER-64. Additionally, we summarize errors associated with power spectrum error estimation that were previously unaccounted for. We focus on a subset of PAPER-64 data in this paper; revised power spectrum limits from the PAPER experiment are presented in a forthcoming paper by Kolopanis et al. and supersede results from previously published PAPER analyses.
We present Atacama Large Millimeter/submillimeter Array (AT,MA) observations of the CiII 158 mu m fine structure line and dust continuum emission from the host galaxies of five redshift 6 quasars. ...The ALMA observations were carried out in the extended array at 0".7 resolution. We have detected the line and dust continuum in all five objects. The derived CII line luminosities are 1.6 x 10 super(9) to 8.7 x 10 super(9) L sub(middot in circle) and the CII-to-FIR luminosity ratios are 2.9-5.1 x 10 super(-4), which is comparable to the values found in other high-redshift quasar-starburst systems and local ultra-luminous infrared galaxies. The sources are marginally resolved and the intrinsic source sizes (major axis FWHM) are constrained to be 0".3-0".6 (i.e., 1.7-3.5 kpc) for the CII line emission and 0".2-0".4 (i.e., 1.2-2.3 kpc) for the continuum. These measurements indicate that there is vigorous star formation over the central few kpc in the quasar host galaxies.
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