Galaxy and Mass Assembly (GAMA): The Weak Environmental Dependence of Quasar Activity at 0.1< z <0.35

Understanding the connection between nuclear activity and galaxy environment remains critical in constraining models of galaxy evolution. By exploiting extensive catalogued data from the Galaxy and Mass Assembly (GAMA) survey, we identify a representative sample of 205 quasars at 0.1 < z < 0.35 and establish a comparison sample of galaxies, closely matched to the quasar sample in terms of both stellar mass and redshift. On scales <1 Mpc, the galaxy number counts and group membership of quasars appear entirely consistent with those of the matched galaxy sample. Despite this, we find that quasars are ∼1.5 times more likely to be classified as the group center, indicating a potential link between quasar activity and cold gas flows or galaxy interactions associated with rich group environments. On scales of ∼a few Mpc, the clustering strength of both samples are statistically consistent and beyond 10 Mpc we find no evidence that quasars trace large scale structures any more than the galaxy control sample. Both populations are found to prefer intermediate-density sheets and filaments to either very high-or very low-density environments. This weak dependence of quasar activity on galaxy environment supports a paradigm in which quasars represent a phase in the lifetime Corresponding author: Clare F. Wethers [email protected] 2 Wethers et al. of all massive galaxies and in which secular processes and a group-centric location are the dominant trigger of quasars at low redshift

Galaxy and Mass Assembly (GAMA): The Weak Environmental Dependence of Quasar Activity at 0.1 \u3c z \u3c 0.35

Understanding the connection between nuclear activity and galaxy environment remains critical in constraining models of galaxy evolution. By exploiting the extensive cataloged data from the Galaxy and Mass Assembly survey, we identify a representative sample of 205 quasars at 0.1 \u3c z \u3c 0.35 and establish a comparison sample of galaxies, closely matched to the quasar sample in terms of both stellar mass and redshift. On scales \u3c1 Mpc, the galaxy number counts and group membership of quasars appear entirely consistent with those of the matched galaxy sample. Despite this, we find that quasars are ∼1.5 times more likely to be classified as the group center, indicating a potential link between quasar activity and cold gas flows or galaxy interactions associated with rich group environments. On scales of ∼a few Mpc, the clustering strengths of both samples are statistically consistent, and beyond 10 Mpc, we find no evidence that quasars trace large-scale structures any more than the galaxy control sample. Both populations are found to prefer intermediate-density sheets and filaments to either very high-density environments or very low-density environments. This weak dependence of quasar activity on galaxy environment supports a paradigm in which quasars represent a phase in the lifetime of all massive galaxies and in which secular processes and a group-centric location are the dominant triggers of quasars at low redshift

Inconsequential Dense Regions and Enhanced Star Formation in Quasar Host Galaxies in the Galaxy and Mass Assembly (GAMA) Survey

Quasars (QSOs) are the brightest objects in the known universe which radiate across the electromagnetic spectrum. They are active nuclei of galaxies that have super- massive black holes (SMBH) at their center. It is believed that merger of gas rich galaxies results in the formation of an active galactic nucleus (AGN). Involved in this process is the obscuring of the central black hole pushing the gas and energy outward of the system through a series of negative feedback which consecutively leads to the quenching of Star Formation (SF) in the resulting galaxy. Science has so far led us to believe that these quiescent hosts are more likely to be found in overdense regions where the probability of mergers triggered AGNs would be higher than in low dense environments. We use the data of more than 330,000 galaxies in the GAMA database and identify the quasars among them using the Large Quasar Astrometric Catalogue-4 (LQAC-4) and study their environment. We aim to find the types of environment these quasar hosts live in, including their stellar parameters and compare their properties against a Monte Carlo simulation of random galaxies selected by the same mass range. We find no evidence of quenched star formation in 207 quasar hosts, but rather an enhanced star formation rate compared to that of inactive galaxies in the same mass range. We find these hosts to have almost twice the mean metallicity and hence a younger stellar population than normal galaxies. They have no direct correlation with the local density of their environments and the same can be said for their relation with the large scale structures they reside in

Abdominal Wall Dyskinesia in a Child Presenting as Belly Dancers’ Syndrome: A Case Report

Belly dancer’s dyskinesia or syndrome is a rare condition characterized by involuntary, undulating, infrequent diaphragm movements. The etiologies for this disorder include nervous system disorders (peripheral or central), drug-induced, psychological, or idiopathic. This article describes a 10-year-old boy with an underlying psychological stressor who suddenly experienced involuntary abdominal wall movements after salbutamol nebulization. After a detailed history, physical examination, and abdominal ultrasound that revealed rapid rhythmic diaphragm movements, the child was diagnosed with salbutamol-induced belly dancer's dyskinesia with an underlying psychological problem. These movements subsided with medical and psychological therapy for two weeks. Belly dancer’s dyskinesia is a complex disorder that is difficult to diagnose but can be managed with medical treatment and psychological counseling alone in a few patients. In contrast, in other cases, surgical intervention may be required