15 research outputs found
GALAXY CRUISE: Deep Insights into Interacting Galaxies in the Local Universe
We present the first results from GALAXY CRUISE, a community (or citizen)
science project based on data from the Hyper Suprime-Cam Subaru Strategic
Program (HSC-SSP). The current paradigm of galaxy evolution suggests that
galaxies grow hierarchically via mergers, but our observational understanding
of the role of mergers is still limited. The data from HSC-SSP are ideally
suited to improve our understanding with improved identifications of
interacting galaxies thanks to the superb depth and image quality of HSC-SSP.
We have launched a community science project, GALAXY CRUISE, in 2019 and
collected over 2 million independent classifications of 20,686 galaxies at z <
0.2. We first characterize the accuracy of the participants' classifications
and demonstrate that it surpasses previous studies based on shallower imaging
data. We then investigate various aspects of interacting galaxies in detail. We
show that there is a clear sign of enhanced activities of super massive black
holes and star formation in interacting galaxies compared to those in isolated
galaxies. The enhancement seems particularly strong for galaxies undergoing
violent merger. We also show that the mass growth rate inferred from our
results is roughly consistent with the observed evolution of the stellar mass
function. The 2nd season of GALAXY CRUISE is currently under way and we
conclude with future prospects. We make the morphological classification
catalog used in this paper publicly available at the GALAXY CRUISE website,
which will be particularly useful for machine-learning applications.Comment: 23 pages, 22 figures, PASJ in press. Data available at
https://galaxycruise.mtk.nao.ac.jp/en/for_researchers.htm
ALMA Observations of Multiple-CO and C Lines Toward the Active Galactic Nucleus of NGC 7469: X-Ray-dominated Region Caught in the Act
We used the Atacama Large Millimeter/submillimeter Array (ALMA) to map
CO( = 1-0), CO( = 2-1), CO( = 3-2), CO(
= 2-1), and [CI](-) emission lines around the type 1 active
galactic nucleus (AGN) of NGC 7469 () at pc resolutions.
The CO lines are bright both in the circumnuclear disk (central pc)
and the surrounding starburst (SB) ring ( kpc diameter), with two
bright peaks on either side of the AGN. By contrast, the [CI](-)
line is strongly peaked on the AGN. Consequently, the brightness temperature
ratio of [CI](-) to CO(2-1) is at the AGN, as
compared to in the SB ring. Our local thermodynamic equilibrium (LTE)
and non-LTE models indicate that the enhanced line ratios (or CI enhancement)
are due to an elevated C/CO abundance ratio () and temperature
( K) around the AGN as compared to the SB ring (abundance ratio
, temperature K), which accords with the picture of the
X-ray-dominated Region (XDR). Based on dynamical modelings, we also provide
CO(1-0)-to- and [CI](-)-to-molecular mass conversion factors at
the central pc of this AGN as and
(K km s pc), respectively.
Our results suggest that the CI enhancement is potentially a good marker of
AGNs that could be used in a new submillimeter diagnostic method toward dusty
environments.Comment: 25 pages, 12 figures, 8 tables. Accepted for publication in ApJ.
Minor updates in a replacemen
Subaru High-z Exploration of Low-luminosity Quasars (SHELLQs). XII. Extended [C ii] Structure (Merger or Outflow) in a z = 6.72 Red Quasar
We present Atacama Large Millimeter/submillimeter Array [C II] 158 μm line and far-infrared (FIR) continuum emission observations toward HSC J120505.09−000027.9 (J1205−0000) at z = 6.72 with a beam size of ∼0 8 × 0 5 (or 4.1 kpc × 2.6 kpc), the most distant red quasar known to date. Red quasars are modestly reddened by dust and are thought to be in rapid transition from an obscured starburst to an unobscured normal quasar, driven by powerful active galactic nucleus (AGN) feedback that blows out a cocoon of interstellar medium. The FIR continuum of J1205−0000 is bright, with an estimated luminosity of LFIR ∼ 3 × 1012 Le. The [C II] line emission is extended on scales of r ∼ 5 kpc, greater than that of the FIR continuum. The line profiles at the extended regions are complex and broad (FWHM ∼ 630–780 km s−1 ). Although it is not practical to identify the nature of this extended structure, possible explanations include (i) companion/merging galaxies and (ii) massive AGN-driven outflows. For the case of (i), the companions are modestly star-forming (∼10 Me yr−1 ) but are not detected by our Subaru optical observations (yAB,5σ = 24.4 mag). For the case of (ii), our lower limit to the cold neutral outflow rate is ∼100 Me yr−1 . The outflow kinetic energy and momentum are both much lower than predicted in energyconserving wind models, suggesting that the AGN feedback in this quasar is not capable of completely suppressing its star formatio
High-pressure behavior of tetragonal barium carbodiimide, BaNCN
The high-pressure behavior of tetragonal barium carbodiimide (BaNCN) was investigated by in-situ highpressure X-ray diffraction measurements and first-principles theoretical calculations. No phase transition or decomposition of tetragonal BaNCN was observed during compression to 6.0 GPa and subsequent decompression to ambient pressure. The bulk modulus estimated from the unit cell volume with respect to the applied pressure was 69(2) GPa, which is comparable to that estimated by first-principles calculations. The theoretical calculations indicate that contraction of the Ba-N bond length has a crucial effect on the volume change in response to pressure, whereas the C-N bonds in the NCN2-anions remain robust against the change in pressure. (C) 2022 Published by Elsevier B.V
Black hole mass measurement using ALMA observations of [CI] and CO emissions in the Seyfert 1 galaxy NGC 7469
International audienceWe present a supermassive black hole (SMBH) mass measurement in the Seyfert 1 galaxy NGC 7469 using Atacama Large Millimeter/submillimeter Array (ALMA) observations of the atomic-[CI](1-0) and molecular-12CO(1-0) emission lines at the spatial resolution of ≍0.3" (or ≍100 pc). These emissions reveal that NGC 7469 hosts a circumnuclear gas disc (CND) with a ring-like structure and a two-arm/bi-symmetric spiral pattern within it, surrounded by a starbursting ring. The CND has a relatively low σgas/V ≍ 0.35 (r ≲ 0.5") and ≍0.19 (r > 0.5"), suggesting that the gas is dynamically settled and suitable for dynamically deriving the mass of its central source. As is expected from X-ray dominated region (XDR) effects that dramatically increase an atomic carbon abundance by dissociating CO molecules, we suggest that the atomic [CI](1-0) emission is a better probe of SMBH masses than CO emission in active galactic nuclei (AGNs). Our dynamical model using the [CI](1-0) kinematics yields a MBH = 1.78-1.10+2.69 × 107 M⊙ and M/LF547M = 2.25-0.43+0.40 (M⊙/L⊙). The model using the 12CO(1-0) kinematics also gives a consistent MBH with a larger uncertainty, up to an order of magnitude, i.e. MBH = 1.60-1.45+11.52 × 107 M⊙. This newly dynamical MBH is ≍2 times higher than the mass determined from the reverberation mapped (RM) method using emissions arising in the unresolved broad-line region (BLR). Given this new MBH, we are able to constrain the specific RM dimensionless scaling factor of f = 7.2-2.5+2.2 for the AGN BLR in NGC 7469. The gas within the unresolved BLR thus has a Keplerian virial velocity component and the inclination of i ≍ 11.0°-2.5+2.2, confirming its face-on orientation in a Seyfert 1 AGN by assuming a geometrically thin BLR model
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ALMA Observations of Multiple CO and C Lines toward the Active Galactic Nucleus of NGC 7469: An X-Ray-dominated Region Caught in the Act
We used the Atacama Large Millimeter/submillimeter Array (ALMA) to map
CO( = 1-0), CO( = 2-1), CO( = 3-2), CO(
= 2-1), and [CI](-) emission lines around the type 1 active
galactic nucleus (AGN) of NGC 7469 () at pc resolutions.
The CO lines are bright both in the circumnuclear disk (central pc)
and the surrounding starburst (SB) ring ( kpc diameter), with two
bright peaks on either side of the AGN. By contrast, the [CI](-)
line is strongly peaked on the AGN. Consequently, the brightness temperature
ratio of [CI](-) to CO(2-1) is at the AGN, as
compared to in the SB ring. Our local thermodynamic equilibrium (LTE)
and non-LTE models indicate that the enhanced line ratios (or CI enhancement)
are due to an elevated C/CO abundance ratio () and temperature
( K) around the AGN as compared to the SB ring (abundance ratio
, temperature K), which accords with the picture of the
X-ray-dominated Region (XDR). Based on dynamical modelings, we also provide
CO(1-0)-to- and [CI](-)-to-molecular mass conversion factors at
the central pc of this AGN as and
(K km s pc), respectively.
Our results suggest that the CI enhancement is potentially a good marker of
AGNs that could be used in a new submillimeter diagnostic method toward dusty
environments
Fas deficiency in mice with the Balb/c background induces blepharitis with allergic inflammation and hyper-IgE production in conjunction with severe autoimmune disease.
Fas (CD95) is a cell surface death receptor belonging to the tumor necrosis factor receptor superfamily, which mediates apoptosis-inducing signaling when activated by Fas ligand or its agonistic antibody. lpr mice with a loss of apoptosis-inducing function mutation in the Fas gene develop systemic autoimmune disease and lymphadenopathy but not allergic inflammation. In the case of Fas mutations including lpr and knockout (KO), background genes determine the incidence and severity of lymphadenopathy and histopathological manifestation of systemic autoimmunity: MRL-lpr/lpr mice and C57BL/6-lpr/lpr or C57BL/6 Fas KO mice develop severe and minimum disease, respectively. We generated Fas KO mice with the Balb/c background that show severer autoimmune phenotypes than MRL-lpr/lpr mice, such as critical infiltration of mononuclear cells into lung, liver and spleen, elevated serum levels of auto-antibodies and a decreased life span. To our astonishment, Balb/c Fas KO mice spontaneously develop blepharitis with not only autoimmune inflammation with deposition of auto-antibody but also allergic inflammation with infiltration by eosinophils and mast cells and show the capacity to strongly increase serum level of IgE and IgG1 along with their aging. Thus, Fas expression regulates development of not only autoimmune disease but also allergic inflammation