We present a simple set of kinematic criteria that can distinguish between galaxies dominated by ordered rotational motion and those involved in major merger events. Our criteria are based on the ...dynamics of the warm ionized gas (as traced by H alpha ) within galaxies, making this analysis accessible to high-redshift systems, whose kinematics are primarily traceable through emission features. Using the method of kinemetry (developed by Krajnovic and coworkers), we quantify asymmetries in both the velocity and velocity dispersion maps of the warm gas, and the resulting criteria enable us to empirically differentiate between nonmerging and merging systems at high redshift. We apply these criteria to 11 of our best-studied rest-frame UV/optical-selected image galaxies for which we have near-infrared integral-field spectroscopic data from SINFONI on the VLT. Of these 11 systems, we find that >50% have kinematics consistent with a single rotating disk interpretation, while the remaining systems are more likely undergoing major mergers. This result, combined with the short formation timescales of these systems, provides evidence that rapid, smooth accretion of gas plays a significant role in galaxy formation at high redshift.
Abstract
The O
iii
5007 Å emission line is the most common tracer of warm, ionized outflows in active galactic nuclei across cosmic time. JWST newly allows us to use mid-IR spectral features at both ...high spatial and spectral resolution to probe these same winds. Here we present a comparison of ground-based, seeing-limited O
iii
and space-based, diffraction-limited S
iv
10.51
μ
m maps of the powerful, kiloparsec-scale outflow in the Type 1 red quasar SDSS J110648.32+480712.3. The JWST data are from the Mid-InfraRed Instrument. There is a close match in resolution between the data sets (∼0.″6), in ionization potential of the O
+2
and S
+3
ions (35 eV) and in line sensitivity (1–2 × 10
−17
erg s
−1
cm
−2
arcsec
−2
). The O
iii
and S
iv
line shapes match in velocity and line width over much of the 20 kpc outflowing nebula, and S
iv
is the brightest line in the rest-frame 3.5–19.5
μ
m range, demonstrating its usefulness as a mid-IR probe of quasar outflows. O
iii
is nevertheless intrinsically brighter and provides better contrast with the point-source continuum, which is strong in the mid-IR. There is a strong anticorrelation of O
iii
/S
iv
with average velocity, which is consistent with a scenario of differential obscuration between the approaching (blueshifted) and receding (redshifted) sides of the flow. The dust in the wind may also obscure the central quasar, consistent with models that attribute red quasar extinction to dusty winds.
We explore the Hα emission in the massive quiescent galaxies observed by the KMOS3D survey at 0.7 < z < 2.7. The Hα line is robustly detected in 20 out of 120 UVJ-selected quiescent galaxies, and we ...classify the emission mechanism using the Hα line width and the N ii/Hα line ratio. We find that AGNs are likely to be responsible for the line emission in more than half of the cases. We also find robust evidence for star formation activity in nine quiescent galaxies, which we explore in detail. The Hα kinematics reveal rotating disks in five of the nine galaxies. The dust-corrected Hα star formation rates are low (0.2–7 M ⊙ yr−1), and place these systems significantly below the main sequence. The 24 μm-based, infrared luminosities, instead, overestimate the star formation rates. These galaxies present a lower gas-phase metallicity compared to star-forming objects with similar stellar mass, and many of them have close companions. We therefore conclude that the low-level star formation activity in these nine quiescent galaxies is likely to be fueled by inflowing gas or minor mergers, and could be a sign of rejuvenation events.
We present the X-ray properties of 108 Dust-Obscured Galaxies (DOGs; F24 m/FR > 1000) in the COSMOS field, all of which are detected in at least three far-infrared bands with the Herschel ...Observatory. Out of the entire sample, 22 are individually detected in the hard 2-8 keV X-ray band by the Chandra COSMOS Legacy survey, allowing us to classify them as AGN. Six (27%) of them are Compton-thick AGN candidates with column densities NH > 1024 cm−2, while 15 are moderately obscured AGNs with 1022 < NH < 1024 cm−2. Additionally, we estimate AGN contributions to the IR luminosity (8-1000 m rest-frame) greater than 20% for 19 DOGs based on SED decomposition using Spitzer/MIPS 24 m and the five Herschel bands (100-500 m). Only 7 of these are detected in X-rays individually. We performed an X-ray stacking analysis for the 86 undetected DOGs. We find that the AGN fraction in DOGs increases with 24 m flux and that it is higher than that of the general 24 m population. However, no significant difference is found when considering only X-ray detections. This strongly motivates the combined use of X-ray and far-IR surveys to successfully probe a wider population of AGNs, particularly for the most obscured ones.
We present a study of the morphology and intensity of star formation in the host galaxies of eight Palomar-Green quasars using observations with the Hubble Space Telescope. Our observations are ...motivated by recent evidence for a close relationship between black hole growth and the stellar mass evolution in its host galaxy. We use narrow-band O iiλ3727, Hβ, O iiiλ5007 and Paα images, taken with the Wide Field Planetary Camera 2 and NICMOS instruments, to map the morphology of line-emitting regions, and, after extinction corrections, diagnose the excitation mechanism and infer star-formation rates. Significant challenges in this type of work are the separation of the quasar light from the stellar continuum and the quasar-excited gas from the star-forming regions. To this end, we present a novel technique for image decomposition and subtraction of quasar light. Our primary result is the detection of extended line-emitting regions with sizes ranging from 0.5 to 5 kpc and distributed symmetrically around the nucleus, powered primarily by star formation. We determine star-formation rates of the order of a few tens of M yr−1. The host galaxies of our target quasars have stellar masses of the order of 1011 M and specific star-formation rates on a par with those of M82 and luminous infrared galaxies. As such they fall at the upper envelope or just above the star-formation mass sequence in the specific star formation versus stellar mass diagram. We see a clear trend of increasing star-formation rate with quasar luminosity, reinforcing the link between the growth of the stellar mass of the host and the black hole mass found by other authors.
We present multiline CO observations of the complex submillimeter galaxy SMM J00266+1708. Using the Zpectrometer on the Green Bank Telescope, we provide the first precise spectroscopic measurement of ...its redshift (z = 2.742). Based on followup CO(1-0), CO(3-2), and CO(5-1) mapping, SMMJ00266+1708 appears to have two distinct components separated by ~500 kms super(-1) that are nearly coincident along our line of sight. The two components show hints of different kinematics, with the blueshifted component dispersion-dominated and the redshifted component showing a clear velocity gradient. CO line ratios differ slightly between the two components, indicating that the physical conditions in their molecular gas may not be alike. We tentatively infer that SMM J00266+1708 is an ongoing merger with a mass ratio of (7.8 + or - 4.0)/sin super(2)(i), with its overall size and surface brightness closely resembling that of other merging systems. We perform large velocity gradient modeling of the CO emission from both components and find that each component's properties are consistent with a single phase of molecular gas (i.e., a single temperatures and density); additional multi-phase modeling of the redshifted component, although motivated by a CO(1-0) size larger than the CO(3-2) size, is inconclusive. SMM J00266+1708 provides evidence of early stage mergers within the submillimeter galaxy population. Continuum observations of J00266 at the ~1" resolution of our observations could not have distinguished between the two components due to their separation (0".73 + or - 0".06), illustrating that the additional velocity information provided by spectral line studies is important for addressing the prevalence of unresolved galaxy pairs in low-resolution submillimeter surveys.
We have used the IRAM Plateau de Bure Interferometer to map CO (3-2) emission from the gravitationally lensed Lyman break galaxy MS 1512-cB58. This is the first detection of a molecular emission line ...in any Lyman break system; its integrated intensity implies a total molecular gas mass of (6.6image) x 10 super(9) himage M sub(o), while its width implies a dynamical mass of (1.0image) x 10 super(10)image i himage M sub(o) (for a flat Omega sub(lambda) = 0.7 cosmology). These estimates are in excellent concordance with nearly all parameters of the system measured at other wavelengths and yield a consistent picture of past and future star formation with no obvious discrepancies requiring explanation by differential lensing. In particular, we find that the age and remaining lifetime of the current episode of star formation are likely to be similar, the surface densities of star formation and molecular gas mass are related by a Schmidt law, and the fraction of baryonic mass already converted into stars is sufficient to account for the observed enrichment of the interstellar medium to 0.4 Z sub(o). Barring substantial gas inflow or a major merger, the stars forming in the current episode will have mass and coevality at z = 0 similar to those of a spiral bulge. Assuming that cB58 is a typical Lyman break galaxy apart from its magnification, its global parameters suggest that the prescriptions for star formation used in some semianalytic models of galaxy evolution require moderate revision, although the general prediction that gas mass fraction should increase with redshift is validated. The length of cB58's star formation episode relative to the time elapsed over the redshift range 2.5 < z < 3.5 strongly argues against scenarios in which observed LBGs cohabit their halos with a large number of similar but "dormant" systems whose starbursts have faded or not yet begun. As a useful empirical result, we find that the observed line/continuum ratio for cB58 is similar to those of high-redshift systems with quite different dust luminosities and nuclear activity levels. Finally, we report the detection of a second source close to the position of the cD elliptical in the z = 0.37 lensing cluster, which may be nonthermal continuum emission from the cD or CO line emission from a hitherto unknown background galaxy at z approx 1.48 or approx2.73.
According to current medical research, mammaglobin (hMAM) is expressed exclusively in the mammary glands of adult women and in mammary tumor cell lines. Therefore, we examined hMAM expression as a ...marker for the detection of carcinoma cells in the peripheral blood of patients with breast cancer (BC).
Blood samples obtained from 114 BC patients at the various stages of their disease and from 68 individuals without BC were screened for hMAM mRNA by a nested reverse transcriptase polymerase chain reaction (RT-PCR) assay.
The assay exhibited a calculated analytical limit of one tumor cell per 10(6) to 10(7) WBCs. None of the samples from peripheral blood of 27 healthy individuals were positive, whereas 29 (25%) of 114 samples from BC patients were positive for hMAM mRNA. hMAM mRNA expression was detected in five (28%) of 18 BC patients at diagnosis, in three (6%) of 53 with no evidence of disease, and in 21 (49%) of 43 with metastatic disease. These results correlate with patients' carcinoembryonic antigen (CEA) plasma level and, to some extent, with estrogen receptor status. Two of 41 samples from patients with malignancies other than BC were also positive.
In contrast to healthy volunteers, hMAM transcripts were detected in the peripheral blood of BC patients. The percentage of positivity relates to the clinical stages of disease, CEA plasma level, and estrogen receptor status. Aberrant hMAM expression might occur occasionally in malignancies other than BC. The clinical relevance of hMAM RT-PCR-based tumor cell detection in the peripheral blood of BC patients should be further evaluated in prospective studies.
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