Subjects: Astronomy >> Galaxy and Cosmology submitted time 2023-02-21
Abstract： Interstellar (ISM) and circumgalactic medium (CGM) around galaxies are linked to several physical processes that drive galaxy evolution. For example, the X-ray emission from the CGM gas around ellipticals has been linked to the AGN feedback occurring in the host. Upcoming telescopes such as HUBS, with ~ 1 eV resolution, can provide us with deep insights about the hot gas properties of such galaxies thus constrain these processes. In this project, we discuss X-ray emission of the ISM and CGM of elliptical galaxies simulated using MACER code. We generate X-ray emission data from the MACER simulations with various feedback models and produce mock observations for an instrument with high spectral resolution, which is a necessary step of selecting sources for the future observations with planned mission such as HUBS. More importantly, we establish connections between the physics of AGN and stellar feedback with the emission spectra from the ISM and CGM to investigate the possibility of using observations to constrain feedback models. We fit the X-ray spectra from these simulations with standard fitting procedures and compare the retrieved physical properties with their counterparts from the simulations to understand whether the future high-resolution observations can reliably reveal the properties of the gas in the galaxies.
Peer Review Status:
Awaiting Review
Subjects: Astronomy >> Astrophysical processes submitted time 2023-02-19
Abstract： Interstellar (ISM) and circumgalactic medium (CGM) around galaxies are linked to several physical processes that drive galaxy evolution. For example, the X-ray emission from the CGM gas around ellipticals has been linked to the AGN feedback occurring in the host. Upcoming telescopes such as HUBS, with ~ 1 eV resolution, can provide us with deep insights about the hot gas properties of such galaxies thus constrain these processes. In this project, we discuss X-ray emission of the ISM and CGM of elliptical galaxies simulated using MACER code. We generate X-ray emission data from the MACER simulations with various feedback models and produce mock observations for an instrument with high spectral resolution, which is a necessary step of selecting sources for the future observations with planned mission such as HUBS. More importantly, we establish connections between the physics of AGN and stellar feedback with the emission spectra from the ISM and CGM to investigate the possibility of using observations to constrain feedback models. We fit the X-ray spectra from these simulations with standard fitting procedures and compare the retrieved physical properties with their counterparts from the simulations to understand whether the future high-resolution observations can reliably reveal the properties of the gas in the galaxies.
Peer Review Status:Awaiting Review
Subjects: Astronomy >> Astrophysical processes submitted time 2023-02-19
Bronwyn Reichardt Chu
Deanne B. Fisher
Alberto D. Bolatto
John Chisholm
Drummond Fielding
Danielle Berg
Alex J. Cameron
Karl Glazebrook
Rodrigo Herrera-Camus
Glenn G. Kacprzak
Laura Lenkić
Miao Li
Daniel K. McPherson
Nikole M. Nielsen
Danail Obreschkow
Ryan J. Rickards Vaught
Karin Sandstrom
Abstract： We compare 500~pc scale, resolved observations of ionised and molecular gas for the $z\sim0.02$ starbursting disk galaxy IRAS08339+6517, using measurements from KCWI and NOEMA. We explore the relationship of the star formation driven ionised gas outflows with colocated galaxy properties. We find a roughly linear relationship between the outflow mass flux ($\dot{\Sigma}_{\rm out}$) and star formation rate surface density ($\Sigma_{\rm SFR}$), $\dot{\Sigma}_{\rm out}\propto\Sigma_{\rm SFR}^{1.06\pm0.10}$, and a strong correlation between $\dot{\Sigma}_{\rm out}$ and the gas depletion time, such that $\dot{\Sigma}_{\rm out} \propto t_{dep}^{-1.1\pm0.06}$. Moreover, we find these outflows are so-called ``breakout" outflows, according to the relationship between the gas fraction and disk kinematics. Assuming that ionised outflow mass scales with total outflow mass, our observations suggest that the regions of highest $\Sigma_{\rm SFR}$ in IRAS08 are removing more gas via the outflow than through the conversion of gas into stars. Our results are consistent with a picture in which the outflow limits the ability for a region of a disk to maintain short depletion times. Our results underline the need for resolved observations of outflows in more galaxies.
Peer Review Status:Awaiting Review
Subjects: Astronomy >> Astrophysical processes submitted time 2023-02-19
Abstract： When a gravitational wave or a graviton travels through an electric or magnetic background, it could convert into a photon with some probability. In this paper, a dipole magnetic field is considered as this kind of background in both the Minkowski spacetime and the curved spacetime in the near-zone of a neutron star. In the former case, we find that the graviton traveling vertically rather than parallel to the background magnetic field could be more effectively converted into an electromagnetic radiation field. In the latter case, we focus on the situation, in which the graviton travels along the radial direction near a neutron star. The radius of a neutron star is about ten kilometers, so the gravitational wave with long wavelength or low frequency may bypass neutron stars by diffraction. For high frequency gravitational wave, the conversion probability is proportional to the distance square as that in the static electric or magnetic background case. The smaller the inclination angle between the dipole field and the neutron star north pole is, the larger magnetic amplitude will be. The term that described curved spacetime will slightly enhance this kind of probability. We estimate that this value is about the order of $\sim 10^{-14}- 10^{-10}$. Therefore, it is expectable that this kind of conversion process may have a potential to open a window for observing high frequency gravitational waves.
Peer Review Status:Awaiting Review
Subjects: Physics >> The Physics of Elementary Particles and Fields submitted time 2016-05-09
Abstract： In this paper we investigate爐he爌ossible direct, non-gravitational爄nteraction燽etween爃olographic燿ark爀nergy�HDE) and燿ark爉atter. Firstly, we start with two simple models with爐he爄nteraction爐erms Q proportional to rho(dm) and Q proportional to rho(de), and then we move on to爐he爂eneral form Q proportional to rho(alpha)(m)rho(beta)(de).燭he燾osmological constraints爋f爐he爉odels are obtained from爐he爅oint analysis爋f爐he爌resent Union 2.1+BAO+CMB+H-0 data. We find that爐he燿ata slightly favor an爀nergy爁low from燿ark爉atter爐o燿ark爀nergy, although爐he爋riginal HDE model still lies in爐he�5.4% confidence level (CL) region. For all models we find c < 1 at爐he�5.4% CL. We show that compared with爐he燾osmic expansion,爐he爀ffect爋f爄nteraction爋n爐he爀volution爋frho(dm) and rho(de) is smaller, and爐he爎elative increment (decrement) amount爋f爐he爀nergy爄n爐he燿ark爉atter燾omponent is constrained to be less than 9% (15%) at爐he�5.4% CL. By introducing爐he爄nteraction, we find that even when c < 1爐he燽ig rip still can be avoided due to爐he爀xistence爋f燼 de Sitter solution at z -> -1. We show that this solution cannot be accomplished in爐he爐wo simple models, while for爐he爂eneral model such a solution can be achieved with a large beta, and爐he燽ig rip may be avoided at爐he�5.4% CL.
Peer Review Status:Awaiting Review
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