On the Discrepancy Between the X-Ray and UV Absorption Measurements of O VI in the Local ISM

The total amount of Ovi present in the interstellar medium (ISM) obtained via absorption measurements in UV and X-ray spectra is currently in disagreement, with the latter being significantly larger (by a factor of 10 or more) than the former. Previous works have proposed that the blend of the Ovi K line (22.032 ) with the Oii K-L12 line (22.04 ) could account for the stronger absorption observed in the X-ray spectra. Here, we present a detailed study of the oxygen absorption in the local ISM, implementing our new model IGMabs which includes photoabsorption cross-sections of highly ionized species of abundant elements as well as turbulence broadening. By analysing high-resolution Chandra spectra of 13 low-mass X-ray binaries (LMXBs) and 29 extragalactic sources, we have estimated the column densities of Oi - Oiii and from Ovi - Oviii along multiple line-of-sights. We find that in most cases the Oii K-L12 line accounts for <30 per cent of the total Ovi K a + Oii K b. We conclude that the amount of Oii predicted by our model is still insufficient to explain the discrepancy between X-ray and UV measurements of Ovi column densities

Sulfur X-ray absorption in the local ISM

We present a study S K-edge using high-resolution HETGS {\it Chandra} spectra of 36 low-mas X-ray binaries. For each source, we have estimated column densities for {\rm S}~{\sc i}, {\rm S}~{\sc ii}, {\rm S}~{\sc iii}, {\rm S}~{\sc xiv}, {\rm S}~{\sc xv} and {\rm S}~{\sc xvi} ionic species, which trace the neutral, warm and hot phases of the Galactic interstellar medium. We also estimated column densities for a sample of interstellar dust analogs. We measured their distribution as a function of Galactic latitude, longitude, and distances to the sources. While the cold-warm column densities tend to decrease with the Galactic latitude, we found no correlation with distances or Galactic longitude. This is the first detailed analysis of the sulfur K-edge absorption due to ISM using high-resolution X-ray spectra.Comment: 8 pages, 6 figure

Chemical enrichment of ICM within the Centaurus cluster I: radial profiles

We examine deep {\it XMM-Newton} EPIC-pn observations of the Centaurus cluster to study the hot intracluster medium (ICM) and radial metal distributions within such an environment. We found that the best-fit spectral model corresponds to a log-normal temperature distribution, with discontinuities around $\sim10$~kpc, $\sim50$~kpc, and $\sim100$~kpc, also observed in the abundances distributions. We measured the radial profiles of O, Si, S, Ar, Ca, and Fe. These profiles reveal prominent negative gradients for distances $<90$~kpc, which then transition to flatter profiles. We modeled X/Fe ratio profiles with a linear combination of SNIcc and SNIa models. The best-fit model suggests a uniform SNIa percentage contribution to the total cluster enrichment, thus supporting an early enrichment of the ICM, with most of the metals present being produced before clustering.Comment: 8 pages, 9 figures. This paper is part of a series on the ICM chemical enrichment using galaxy clusters XMM-Newton observations for which the velocity structure has been measured. Related series papers: arXiv:2302.0428

The Soft-Excess in Mrk 509: Warm Corona or Relativistic Reflection?

We present the analysis of the first NuSTAR observations ($\sim 220$ ks), simultaneous with the last SUZAKU observations ($\sim 50$ ks), of the active galactic nucleus of the bright Seyfert 1 galaxy Mrk 509. The time-averaged spectrum in the $1-79$ keV X-ray band is dominated by a power-law continuum ($\Gamma\sim 1.8-1.9$), a strong soft excess around 1 keV, and signatures of X-ray reflection in the form of Fe K emission ($\sim 6.4$ keV), an Fe K absorption edge ($\sim 7.1$ keV), and a Compton hump due to electron scattering ($\sim 20-30$ keV). We show that these data can be described by two very different prescriptions for the soft excess: a warm ($kT\sim 0.5-1$ keV) and optically thick ($\tau\sim10-20$) Comptonizing corona, or a relativistically blurred ionized reflection spectrum from the inner regions of the accretion disk. While these two scenarios cannot be distinguished based on their fit statistics, we argue that the parameters required by the warm corona model are physically incompatible with the conditions of standard coronae. Detailed photoionization calculations show that even in the most favorable conditions, the warm corona should produce strong absorption in the observed spectrum. On the other hand, while the relativistic reflection model provides a satisfactory description of the data, it also requires extreme parameters, such as maximum black hole spin, a very low and compact hot corona, and a very high density for the inner accretion disk. Deeper observations of this source are thus necessary to confirm the presence of relativistic reflection, and to further understand the nature of its soft excess.Comment: Accepted for publication in ApJ, 18 pages, 7 figure

Smart Panking : uma aplicação para estacionamento em cidades inteligentes

The world is experiencing two major transformations: the number of people living in urban areas surpassing the number of people in rural areas and a technological revolution changing the lives of billions of people. With more people living in cities, the problems they face are intensified and the response to these problems increasingly involves the use of a lot of technology, from which emerges the concept of Smart City. In order to deal with one of the most critical problems of cities, urban mobility, this work seeks to understand its causes and what interventions could be undertaken. One of the most prominent problems that impacts the urban mobility is the high number of vehicles circulating in cities and one of the challenges is to manage this fleet of vehicles in order to reduce congestion, facilitating mobility and consequently reducing the amount of exhaust gases in the atmosphere. Since one of the causes of this problem is the time spent by drivers looking for parking spaces, one solution is to minimize it. For this purpose a Systematic Literature Review of primary studies that were inserted in this context was carried out and through a Product Research in the Market, followed by the application of a questionnaire to stakeholders, relevant characteristics were extracted for the development of a solution for this scenario. Therefore, the objective of this work was to create a tool that intelligently optimizes the process of supply and demand of parking spots, considering the growing number of vehicles and the limited space of cities as a contribution to the development of Smart Cities.O mundo está vivenciando duas grandes transformações: o número de pessoas vivendo em zonas urbanas ultrapassando o número de pessoas em zonas rurais e uma revolução tecnológica mudando a vida de bilhões de pessoas. Com mais pessoas vivendo nas cidades, os problemas que elas enfrentam são intensificados e a resposta a esses problemas envolve cada vez mais o emprego de muita tecnologia, de onde emerge o conceito de Cidade Inteligente. Com o intuito de lidar com um dos problemas mais crucias das cidades, a mobilidade urbana, este trabalho procurou levantar as suas causas e quais intervenções poderiam ser realizadas. Um dos problemas mais proeminentes que gera impacto na mobilidade urbana é o crescimento da quantidade de veículos circulando nas cidades e um dos desafios é gerenciar esta frota de veículos buscando diminuir o congestionamento, facilitando a mobilidade e consequentemente reduzindo a quantidade de gases expelidos na atmosfera. Uma vez que uma das causas deste problema é o tempo gasto pelos motoristas na procura por vagas para estacionar, uma solução é minimizar esta causa. Para este fim foi realizada uma Revisão Sistemática dos estudos primários que estão inseridos neste contexto e por meio de uma Pesquisa de Produtos no Mercado, seguido da aplicação de um questionário para stakeholders foram extraídas características relevantes para o desenvolvimento de uma solução para este cenário. Sendo assim o objetivo deste trabalho foi criar uma ferramenta que otimiza de forma inteligente o processo de oferta e procura de vagas de estacionamento, tendo em vista o número crescente de veículos e o espaço limitado das cidades como contribuição para o desenvolvimento das Cidades Inteligentes.São Cristóvã

Implications of the Warm Corona and Relativistic Reflection Models for the Soft Excess in Mrk 509

We present the analysis of the first Nuclear Spectroscopic Telescope Array observations (~220 ks), simultaneous with the last Suzaku observations (~50 ks), of the active galactic nucleus of the bright Seyfert 1 galaxy Mrk 509. The time-averaged spectrum in the 1–79 keV X-ray band is dominated by a power-law continuum (Γ ~ 1.8–1.9), a strong soft excess around 1 keV, and signatures of X-ray reflection in the form of Fe K emission (~6.4 keV), an Fe K absorption edge (~7.1 keV), and a Compton hump due to electron scattering (~20–30 keV). We show that these data can be described by two very different prescriptions for the soft excess: a warm (kT ~ 0.5–1 keV) and optically thick (τ ~ 10–20) Comptonizing corona or a relativistically blurred ionized reflection spectrum from the inner regions of the accretion disk. While these two scenarios cannot be distinguished based on their fit statistics, we argue that the parameters required by the warm corona model are physically incompatible with the conditions of standard coronae. Detailed photoionization calculations show that even in the most favorable conditions, the warm corona should produce strong absorption in the observed spectrum. On the other hand, while the relativistic reflection model provides a satisfactory description of the data, it also requires extreme parameters, such as maximum black hole spin, a very low and compact hot corona, and a very high density for the inner accretion disk. Deeper observations of this source are thus necessary to confirm the presence of relativistic reflection and further understand the nature of its soft excess

The eROSITA view of the Abell 3391/95 field: The Northern Clump. The largest infalling structure in the longest known gas filament observed with eROSITA, XMM-Newton, and Chandra

SRG/eROSITA PV observations revealed the A3391/95 cluster system and the Northern Clump (MCXC J0621.7-5242 galaxy cluster) are aligning along a cosmic filament in soft X-rays, similarly to what has been seen in simulations before. We aim to understand the dynamical state of the Northern Clump as it enters the atmosphere ($3\times R_{200}$) of A3391. We analyzed joint eROSITA, XMM-Newton, and Chandra observations to probe the morphological, thermal, and chemical properties of the Northern Clump from its center out to a radius of 988 kpc ($R_{200}$). We utilized the ASKAP/EMU radio data, DECam optical image, and Planck y-map to study the influence of the WAT radio source on the Northern Clump central ICM. From the Magneticum simulation, we identified an analog of the A3391/95 system along with an infalling group resembling the Northern Clump. The Northern Clump is a WCC cluster centered on a WAT radio galaxy. The gas temperature over $0.2-0.5R_{500}$ is $k_BT_{500}=1.99\pm0.04$ keV. We employed the $M-T$ scaling relation and obtained a mass estimate of $M_{500}=(7.68\pm0.43)\times10^{13}M_{\odot}$ and $R_{500}=(636\pm12)$ kpc. Its atmosphere has a boxy shape and deviates from spherical symmetry. We identify a southern surface brightness edge, likely caused by subsonic motion relative to the filament gas. At $\sim\! R_{500}$, the southern atmosphere appears to be 42% hotter than its northern atmosphere. We detect a downstream tail pointing toward the north with a projected length of $\sim318$ kpc, plausibly the result of ram pressure stripping. The analog group in the Magneticum simulation is experiencing changes in its gas properties and a shift between the position of the halo center and that of the bound gas, while approaching the main cluster pair.Comment: 24 pages, 17 figures (main text), 6 figures (appendix). Submitted to A&A for the Special Issue: The Early Data Release of eROSITA and Mikhail Pavlinsky ART-XC on the SRG Mission. For more information, see https://astro.uni-bonn.de/~averonica/NorthernClump/eROSITA_A3391_Northern_Clump_AIfA.htm

Implications of the Warm Corona and Relativistic Reflection Models for the Soft Excess in Mrk 509

We present the analysis of the first Nuclear Spectroscopic Telescope Array observations (~220 ks), simultaneous with the last Suzaku observations (~50 ks), of the active galactic nucleus of the bright Seyfert 1 galaxy Mrk 509. The time-averaged spectrum in the 1–79 keV X-ray band is dominated by a power-law continuum (Γ ~ 1.8–1.9), a strong soft excess around 1 keV, and signatures of X-ray reflection in the form of Fe K emission (~6.4 keV), an Fe K absorption edge (~7.1 keV), and a Compton hump due to electron scattering (~20–30 keV). We show that these data can be described by two very different prescriptions for the soft excess: a warm (kT ~ 0.5–1 keV) and optically thick (τ ~ 10–20) Comptonizing corona or a relativistically blurred ionized reflection spectrum from the inner regions of the accretion disk. While these two scenarios cannot be distinguished based on their fit statistics, we argue that the parameters required by the warm corona model are physically incompatible with the conditions of standard coronae. Detailed photoionization calculations show that even in the most favorable conditions, the warm corona should produce strong absorption in the observed spectrum. On the other hand, while the relativistic reflection model provides a satisfactory description of the data, it also requires extreme parameters, such as maximum black hole spin, a very low and compact hot corona, and a very high density for the inner accretion disk. Deeper observations of this source are thus necessary to confirm the presence of relativistic reflection and further understand the nature of its soft excess