26 research outputs found
A low-luminosity type-1 QSO sample: II. Tracing circumnuclear star formation in HE 1029-1831 with SINFONI
Circumnuclear star formation and AGN feedback is believed to play a critical
role in the context of galaxy evolution. The low-luminosity QSO (LLQSO) sample
that contains 99 of the closest AGN with redshift z<=0.06 fills the gap between
the local AGN population and high-redshift QSOs that is essential to understand
the AGN evolution with redshift. In this paper, we present the results of
near-infrared H+K-integral field spectroscopy of the inner kiloparsecs of the
LLQSO HE 1029-1831 with SINFONI. Line maps show that ionized hydrogen gas is
located in spiral arms within the stellar bar and in a circumnuclear ring. Line
fluxes and diagnostic line ratios indicate recent or ongoing star formation in
the circumnuclear region and the presence of young and intermediate-age stellar
populations in the bulge. In particular, we find traces of an intense starburst
in the circumnuclear region that has begun around 100 Myr ago but has declined
to a fraction of the maximum intensity now. We estimate the dynamical bulge
mass and find that the galaxy follows published M_BH-M_bulge relations.
However, bulge-disk decomposition of the K-band image with BUDDA reveals that
HE 1029-1831 does not follow the M_BH-L_bulge relations of inactive galaxies.
We conclude that the deviation from M_BH-L_bulge relations of inactive galaxies
in this source is rather caused by young stellar populations and not by an
undermassive black hole.Comment: 16 pages, 11 figures, submitted to A&A, comments welcom
Single-cell sequencing of human midbrain reveals glial activation and a Parkinson-specific neuronal state
Idiopathic Parkinson's disease is characterized by a progressive loss of dopaminergic neurons, but the exact disease etiology remains largely unknown. To date, Parkinson's disease research has mainly focused on nigral dopaminergic neurons, although recent studies suggest disease-related changes also in non-neuronal cells and in midbrain regions beyond the substantia nigra. While there is some evidence for glial involvement in Parkinson's disease, the molecular mechanisms remain poorly understood. The aim of this study was to characterize the contribution of all cell types of the midbrain to Parkinson's disease pathology by single-nuclei RNA sequencing and to assess the cell type-specific risk for Parkinson's disease employing the latest genome-wide association study. We profiled >41 000 single-nuclei transcriptomes of postmortem midbrain from six idiopathic Parkinson's disease patients and five age-/sex-matched controls. To validate our findings in a spatial context, we utilized immunolabeling of the same tissues. Moreover, we analyzed Parkinson's disease-associated risk enrichment in genes with cell type-specific expression patterns. We discovered a neuronal cell cluster characterized by CADPS2 overexpression and low TH levels, which was exclusively present in IPD midbrains. Validation analyses in laser-microdissected neurons suggest that this cluster represents dysfunctional dopaminergic neurons. With regard to glial cells, we observed an increase in nigral microglia in Parkinson's disease patients. Moreover, nigral idiopathic Parkinson's disease microglia were more amoeboid, indicating an activated state. We also discovered a reduction in idiopathic Parkinson's disease oligodendrocyte numbers with the remaining cells being characterized by a stress-induced upregulation of S100B. Parkinson's disease risk variants were associated with glia- and neuron-specific gene expression patterns in idiopathic Parkinson's disease cases. Furthermore, astrocytes and microglia presented idiopathic Parkinson's disease-specific cell proliferation and dysregulation of genes related to unfolded protein response and cytokine signaling. While reactive patient astrocytes showed CD44 overexpression, idiopathic Parkinson's disease-microglia revealed a pro-inflammatory trajectory characterized by elevated levels of IL1B, GPNMB, and HSP90AA1. Taken together, we generated the first single-nuclei RNA sequencing dataset from the idiopathic Parkinson's disease midbrain, which highlights a disease-specific neuronal cell cluster as well as 'pan-glial' activation as a central mechanism in the pathology of the movement disorder. This finding warrants further research into inflammatory signaling and immunomodulatory treatments in Parkinson's disease
Unveiling the nucleus of
Aims. We present the results of near-infrared (NIR) H + K European Southern Observatory SINFONI integral field spectroscopy (IFS) of the Seyfert 2 galaxy NGC 717
AGN with faint broad line regions: Some ‘True’-Seyfert 2s might be Narrow Line Seyfert 1s
Etiology of chronic kidney disease influences on values of lipids, lipoproteins, apolipoproteins and lipid indices
A low-luminosity type-1 QSO sample
We present near-infrared (NIR) H + K-band long-slit spectra of eleven galaxies that were obtained with SOFI at the NTT (ESO). The galaxies are chosen from the low-luminosity type-1 quasi-stellar object (LLQSO) sample, which comprises the 99 closest (z ≤ 0.06) QSOs from the Hamburg/ESO survey for bright UV-excess QSOs. These objects are ideal targets to study the gap between local Seyfert galaxies and high-redshift quasars because they show much stronger AGN activity than local objects, but are still close enough for a detailed structural analysis. We fit hydrogen recombination, molecular hydrogen, and [Fe i
ALMA-backed NIR high resolution integral field spectroscopy of the NUGA galaxy NGC 1433
Aims. We present the results of near-infrared (NIR) H- and K-band European Southern Observatory SINFONI integral field spectroscopy (IFS) of the Seyfert 2 galaxy NGC 143