ABSTRACT JWST observations indicate a surprising excess of luminous galaxies at z ∼ 10 and above, consistent with efficient conversion the accreted gas into stars, unlike suppression star formation by feedback later times. We show that high densities low metallicities this epoch guarantee efficiency (SFE) in most massive dark-matter haloes. Feedback-free starbursts (FFBs) occur when free-fall time is shorter than ∼$1\, {\rm Myr}$, below for low-metallicity stars to develop winds supernovae....

We extend the analysis of a physical model within standard cosmology that robustly predicts high star-formation efficiency (SFE) in massive galaxies at cosmic dawn due to feedback-free starbursts (FFBs). This implies an excess bright $z 10$ compared models based on low SFE later epochs, is indicated by JWST observations. Here we provide observable predictions galaxy properties analytic FFB scenario. These can be with simulations and use approximate as function redshift mass, assuming maximum...

Using hydrodynamical simulations, we show for the first time that an episode of star formation in center Milky Way, with a star-formation-rate (SFR) $\sim 0.5$ M$_\odot$ yr$^{-1}$ 30$ Myr, can produce bubbles resemble Fermi Bubbles (FBs), when viewed from solar position. The morphology, extent and multi-wavelength observations FBs, especially X-rays, constrain various physical parameters such as SFR, age, circum-galactic medium (CGM) density. We interaction CGM Galactic wind driven by...

ABSTRACT Recently, a new population of circular radio (∼GHz) objects has been discovered at high Galactic latitudes, called the odd circles (ORCs). A fraction ORCs encircles massive galaxies in sky with stellar mass ∼1011 M⊙ situated z = 0.2–0.6, suggesting possible physical connection. In this paper, we explore possibility that these originate from accretion shocks/virial shocks around (${\gtrsim} 10^{13}\, \ {\rm M}_\odot$) dark matter halo ∼ 0.5. We found flux density emitting shell is...

Using hydrodynamic simulations, we study the mass loss due to supernova-driven outflows from Milky Way type disk galaxies, paying particular attention effect of extended hot halo gas. We find that total at inner radii scales roughly linearly with stars formed, and loading factor virial radius can be several times its value because swept up The temperature distribution outflowing material in region ($\sim $10 kpc) is bimodal nature, peaking $10^5$ K $10^{6.5}$ K, responsible for optical X-ray...

Abstract One of the leading explanations for origin Fermi Bubbles is past jet activity in Galactic center supermassive black hole Sgr A * . The claimed jets are often assumed to be perpendicular plane. Motivated by orientation pc-scale nuclear stellar disk and gas streams, as well a low inclination accretion around inferred Event Horizon Telescope, we perform hydrodynamical simulations significantly tilted relative rotation axis. observed axisymmetry hemisymmetry (north–south symmetry)...

Abstract Accreting supermassive black holes frequently power jets that interact with the interstellar medium (ISM)/circumgalactic medium, regulating star formation in galaxy. Highly supersonic launched by active galactic nuclei (AGN) a cocoon confines them and shocks ambient medium. We build on models of narrow conical interacting smooth including effect dense clouds, which are an essential ingredient multiphase ISM. The key physical this model is clouds along jet beam strongly decelerate...

We constrain the origin of Fermi bubbles using 2D hydrodynamical simulations both star formation-driven and black hole accretion-driven wind models. compare our results with recent observations O viii to vii line ratio within near bubbles. Our suggest that independent driving mechanisms, a low-luminosity (⁠|$\mathcal {L} \sim 0.7\hbox{--}1\times 10^{41}$| erg s−1) energy injection best reproduces observed for which shock temperature is ≈3 × 106 K. Assuming Galactic halo be 2 K, we estimate...

The origin of North Polar Spur (NPS) and Loop-I has been debated over almost half a century is still unresolved. Most the confusion caused by absence any prominent counterparts these structures in southern Galactic hemisphere (SGH). This also led to doubts claimed connection between NPS Fermi Bubbles (FBs). I show this paper, that such asymmetries both X-rays $\gamma$-rays can be easily produced if circumgalactic medium (CGM) density only smaller $\approx 20\%$ than northern counterpart case...

We address a simple model where the Kennicutt-Schmidt (KS) relation between macroscopic densities of star-formation rate (SFR, $\rho_{\rm sfr}$) and gas ($n$) in galactic discs emerges from self-regulation SFR via supernova feedback. It arises physics bubbles, insensitive to microscopic recipe not explicitly dependent on gravity. The key is that filling factor SFR-suppressed bubbles self-regulates constant, $f\sim 0.5$. Expressing bubble fading radius time terms $n$, $f \propto S\,n^{-s}$...

Abstract We present hydrodynamical simulations of galactic winds from star-forming galaxies including nonequilibrium ionization and frequency-dependent radiative transfer, processes that have remained largely unaccounted for in wind studies. consider radiation massive stars, the metagalactic UV/X-ray background, self-radiation supernovae heated gas. compare our results to classical solutions show importance newly included physical toward observations ions such as O iii , vi vii viii plus...

Accreting supermassive black holes (SMBHs) frequently power jets that interact with the interstellar/circumgalactic medium (ISM/CGM), regulating star-formation in galaxy. Highly supersonic launched by active galactic nuclei (AGN) a cocoon confines them and shocks ambient medium. We build upon models of narrow conical interacting smooth medium, to include effect dense clouds are an essential ingredient multiphase ISM. The key physical this model is along jet-beam strongly decelerate jet-head,...

We study the effects of mass and energy injection due to OB associations spread across rotating disc a Milky Way-type galaxy, with help 3D hydrodynamic simulations. compare resulting X-ray emission that produced from central region. find predicted image shows filamentary structure arises even in absence gas inhomogeneity. This stems warm clumps made material being lifted by injected gas. show as much half total comes regions surrounding are mix disk scenario has potential explain origin...

The bipolar, nonthermal, high-latitude lobes known as the Fermi bubbles (FBs) are thought to originate from a massive energy release near Galactic centre (GC). We constrain FB engine and circumgalactic medium (CGM) by analytically numerically modeling edges strong forward shocks, inferred recent observations. A non-directed produces shocks too spherical account for observations even maximally disc, critical CGM rotation, or injection effectively offset GC. In contrast, collimated nearly...

We extend the analysis of a physical model within standard cosmology that robustly predicts high star-formation efficiency (SFE) in massive galaxies at cosmic dawn due to feedback-free starbursts (FFB). It implies an excess bright z>~10 compared models based on low SFE later epochs, is indicated by JWST observations. Here we provide observable predictions analytic FFB scenario, be with simulations and use approximate as function redshift mass, assuming maximum 0.2~1 regime. From this, derive...

We study the diffuse X-ray luminosity ($L_X$) of star forming galaxies using 2-D axisymmetric hydrodynamical simulations and analytical considerations supernovae (SNe) driven galactic outflows. find that mass loading outflows, a crucial parameter for determining luminosity, is constrained by availability gas in central region, competition between cooling expansion. show allowed range factor can explain observed scaling $L_X$ with formation rate (SFR) as $L_X \propto$ SFR$^2$ SFR $\gtrsim 1$...

We present numerical simulations of the evolution a supernova (SN) remnant expanding into uniform background medium with density $n_H = 1.0$ cm$^{-3}$ and temperature $10^4$ K. include dynamically evolving non-equilibrium ionisation (NEI) network (consisting all ions H, He, C, N, O, Ne, Mg, Si, S, Fe), frequency dependent radiation transfer (RT), thermal conduction, simple dust model, intra-coupled to each other hydrodynamics. assume spherical symmetry. Photo-ionisation, losses,...

ABSTRACT We study the survival of giant clumps in high-redshift disc galaxies, short-lived (S) versus long-lived (L), and two L subtypes, via analytic modelling simulations. develop a criterion for clump survival, with/without gas, based on survivability parameter S. It compares energy sources by supernova feedback gravitational contraction to binding losses outflows turbulence dissipation. The properties are derived from Toomre instability, approaching virial/Jeans equilibrium, deposit uses...

We introduce a new general-purpose time-dependent ionisation network (IN) and radiation transport (RT) module in the magneto-hydrodynamic (MHD) code PLUTO. Our is reliable for temperatures ranging from 5e3 to 3e8 K, includes all states of H, He, C, N, O, Ne, Mg, Si, S Fe making it suitable studying variety astrophysical scenarios. Radiation loss each ion-electron pair calculated using CLOUDY-17 data on-the-fly. Photo-ionisation charge exchange are chemical heating mechanisms. The IN fully...

Galactic outflows are ubiquitous in galaxies containing active star formation or supermassive black hole activity. The presence of a large-scale outflow from the center our own Galaxy was confirmed after discovery two large ($\sim 8-10$ kpc) \gamma-ray bubbles using \textit{Fermi-LAT} telescope. These bubbles, known as Fermi Bubbles, highly symmetric about disk well around rotation axis and appear to emanate Galaxy. sharp edges these suggest that they related outflow. surrounded by even...

We present a set of controlled hydrodynamical simulations to study the effects strong galactic outflows on density and temperature structures, associated X-ray signatures, extra-planar circumgalactic gas. consider three initial state models, isothermal, isentropic, rotating cooling-flow, for hot medium (CGM) into which are driven. The energy sources either stellar winds supernovae, or active nuclei. injection rates in range $10^{40} < \dot{E}_{\rm inj} <10^{44.5}$ erg s$^{-1}$, compute...

ABSTRACT We present a set of controlled hydrodynamical simulations to study the effects strong galactic outflows on density and temperature structures, associated X-ray signatures, extra-planar circumgalactic gas. consider three initial state models, isothermal, isentropic, rotating cooling-flow, for hot medium (CGM) into which are driven. The energy sources either stellar winds supernovae, or active nuclei. injection rates in range $10^{40} \lt \dot{E}_{\rm inj} 10^{44.5}$ erg s−1, compute...

The origin of warm ions in the circum-galactic medium (CGM) surrounding massive galaxies remains a mystery. In this paper, we argue that significant fraction observed warm-ion columns may arise intergalactic (IGM) galactic halos. We use simple spherical collapse model dark matter (DM) halos and their baryonic content to compute evolving ion fractions within outside virial show photoionized IGM produce thick blanket around CGM, thereby contaminating CGM observations. find contributes $> 75\%$...