This project is focused on evaluating the slowly-varying ground layer seeing component at the optical telescopes of ARIES. To achieve this, we assembled the instrument, consisting of a filter wheel, ...a CCD camera, and a tip-tilt enabled transparent glass plate integrated within an off-the-shelf unit termed as the AO (Adaptive Optics) unit. The instrument developed by us was deployed on the 1.04-m f/13 Sampurnanand telescope at Manora Peak and the 1.3-m f/4 telescope at Devasthal. This instrument measures the average instantaneous slope (tip/tilt) of the incoming wavefront over the telescope aperture via a fast (within the atmospheric coherence time) sampled image and corrects it via a software-controlled oscillating (tipping/tilting) single thin glass plate. The night observations revealed that the slowly-varying seeing component is significant at both observatories and can be effectively controlled to enhance the sharpness of the celestial images at the two sites. The most significant improvement was measured from 5 arcsec of uncorrected FWHM of a star to 3.4 arcsec of corrected FWHM in the 1.04-m telescope in the evening hours.
SiRGraF Integrated Tool for Coronal dynaMics (SITCoM) is based on the Simple Radial Gradient Filter used to filter the radial gradient in the white-light coronagraph images and bring out dynamic ...structures. SITCoM has been developed in Python and integrated with SunPy and can be installed by users with the command pip install sitcom. This enables the user to pass the white-light coronagraph data to the tool and generate radially filtered output with an option to save in various formats as required. We implemented the functionality of tracking the transients such as coronal mass ejections, outflows, and plasma blobs, using height–time plots and deriving their kinematics. In addition, SITCoM also supports oscillation and wave studies such as for streamer waves. This is performed by creating a distance–time plot at a user-defined location (artificial slice) and fitting a sinusoidal function to derive the properties of waves, such as time period, amplitude, and damping time (if any). We provide the option to manually or automatically select the data points to be used for fitting. SITCoM is a tool to analyze some properties of coronal dynamics quickly. We present an overview of the SITCoM with the applications for deriving coronal dynamics’ kinematics and oscillation properties. We discuss the limitations of this tool along with prospects for future improvement.
ABSTRACT
We present here results from a survey of intervening C iv absorbers at z < 0.16 conducted using 223 sightlines from the Hubble Spectroscopic Legacy Archive. Most systems (83%) out of the ...total sample of 69 have simple kinematics with 1 or 2 C iv components. In the 22 C iv systems with well constrained H i column densities, the temperatures from the b-values imply predominantly photoionized plasma (T ≤ 105 K) and non-thermal dynamics. These systems also have solar or higher metallicities. We obtain a C iv line density of $\mathrm{ d}\mathcal {N}/\mathrm{ d}X = 5.1\pm 1.0$ for $\log N(\rm {C}\, \rm {{iv}})~(\rm {cm}^{-2})\ge 12.9$, and $\Omega _{\rm {C}\, \rm {\rm {iv}}}=(8.01\pm 1.62) \times 10^{-8}$ for $12.9 \le \log N(\rm {C}\, \rm {{iv}})~(\rm {cm}^{-2}) \le 15.0$. The C iv bearing diffuse gas in the z < 0.16 Universe has a metallicity of (2.07 ± 0.43) × 10−3 Z⊙, an order of magnitude more than the metal abundances in the IGM at high redshifts (z ≳ 5), and consistent with the slow build-up of metals in the diffuse circum/intergalactic space with cosmic time. For z < 0.015 (complete above L > 0.01L⋆), the Sloan Digital Sky Survey provides a tentative evidence of declining covering fraction for strong C iv (N > 1013.5 cm−2) with ρ (impact parameter) and ρ/Rvir. However, the increase at high separations suggests that strong systems are not necessarily coincident with such galaxies. We also find that strong C iv absorption at z < 0.051 is not coincident with galaxy overdense regions complete for L > 0.13L⋆.
This project is focused on evaluating the slowly-varying ground layer seeing component at the optical telescopes of ARIES. To achieve this, we assembled the instrument, consisting of a filter wheel, ...a CCD camera, and a tip-tilt enabled transparent glass plate integrated within an off-the-shelf unit termed as the AO (Adaptive Optics) unit. The instrument developed by us was deployed on the 1.04-m f/13 Sampurnanand telescope at Manora Peak and the 1.3-m f/4 telescope at Devasthal. This instrument measures the average instantaneous slope (tip/tilt) of the incoming wavefront over the telescope aperture via a fast (within the atmospheric coherence time) sampled image and corrects it via a software-controlled oscillating (tipping/tilting) single thin glass plate. The night observations revealed that the slowly-varying seeing component is significant at both observatories and can be effectively controlled to enhance the sharpness of the celestial images at the two sites. The most significant improvement was measured from 5 arcsec of uncorrected FWHM of a star to 3.4 arcsec of corrected FWHM in the 1.04-m telescope. in the evening hours.
SiRGraF Integrated Tool for Coronal dynaMics (SITCoM) is based on Simple Radial Gradient Filter (SiRGraF) used to filter the radial gradient in the white-light coronagraph images and bring out ...dynamic structures. SITCoM has been developed in Python and integrated with SunPy and can be installed by users with the command pip install sitcom. This enables the user to pass the white-light coronagraph data to the tool and generate radially filtered output with an option to save in various formats as required. We have implemented the functionality of tracking the transients such as coronal mass ejections (CMEs), outflows, plasma blobs, etc., using height-time plots and deriving their kinematics. In addition, SITCoM also supports oscillation and waves studies such as for streamer waves. This is done by creating a distance-time plot at a user-defined location (artificial slice) and fitting a sinusoidal function to derive the properties of waves, such as time period, amplitude, and damping time (if any). We provide the provision to manually or automatically select the data points to be used for fitting. SITCoM is a tool to analyze some properties of coronal dynamics quickly. We present an overview of the SITCoM with the applications for deriving coronal dynamics' kinematics and oscillation properties. We discuss the limitations of this tool along with prospects for future improvement.
We present here results from a survey of intervening C IV absorbers at \(z < 0.16\) conducted using 223 sightlines from the Hubble Spectroscopic Legacy Archive. Most systems (83%) out of the total ...sample of 69 have simple kinematics with 1 or 2 C IV components. In the 22 C IV systems with well constrained H I column densities, the temperatures from the \(b\)-values imply predominantly photoionized plasma (\(T\leq 10^5\) K) and non-thermal dynamics. These systems also have solar or higher metallicities. We obtain a C IV line density of \(d\mathcal{N}/dX = 5.1\pm 1.0\) for \(\log N(C~IV)~(cm^{-2})\geq12.9\), and \(\Omega_{C~IV}=(8.01\pm 1.62) \times 10^{-8}\) for \(12.9 \leq \log N(C~IV)~(cm^{-2}) \leq 15.0\). The C IV bearing diffuse gas in the \(z < 0.16\) Universe has a metallicity of \((2.07~{\pm}~0.43)~\times~10^{-3}\) Z\(_{\odot}\), an order of magnitude more than the metal abundances in the IGM at high redshifts (\(z \gtrsim 5\)), and consistent with the slow build-up of metals in the diffuse circum/intergalactic space with cosmic time. For \(z<0.015\) (complete above \(L>0.01L^\star\)), the Sloan Digital Sky Survey provides a tentative evidence of declining covering fraction for strong C IV (\(N>10^{13.5}~cm^{-2}\)) with \(\rho\) (impact parameter) and \(\rho/R_\mathrm{vir}\). However, the increase at high separations suggests that strong systems are not necessarily coincident with such galaxies. We also find that strong C IV absorption at \(z<0.051\) is not coincident with galaxy over-dense regions complete for \(L>0.13L^\star\)
We present an analysis of the galaxy environment and physical properties of a
partial Lyman limit system at z = 0.83718 with HI and metal line components
closely separated in redshift space ($|\Delta ...v| \approx 400$ km/s) towards the
background quasar HE1003+0149. The HST/COS far-ultraviolet spectrum provides
coverage of lines of oxygen ions from OI to OV. Comparison of observed spectral
lines with synthetic profiles generated from Bayesian ionization modeling
reveals the presence of two distinct gas phases in the absorbing medium. The
low-ionization phase of the absorber has sub-solar metallicities (1/10-th
solar) with indications of C/O < 0 in each of the components. The OIV and OV
trace a more diffuse higher-ionization medium with predicted HI column
densities that are $\approx 2$ dex lower. The quasar field observed with
VLT/MUSE reveals three dwarf galaxies with stellar masses of $M^* \sim 10^{8} -
10^{9}$ M$_\odot$, and with star formation rates of $\approx 0.5 - 1$ M$_\odot$
yr$^{-1}$, at projected separations of $\rho/R_{\mathrm{vir}} \approx 1.8 -
3.0$ from the absorber. Over a wider field with projected proper separation of
$\leq 5$ Mpc and radial velocity offset of $|\Delta v| \leq 1000$ km/s from the
absorber, 21 more galaxies are identified in the $VLT$/VIMOS and Magellan deep
galaxy redshift surveys, with 8 of them within $1$ Mpc and $500$ km/s,
consistent with the line of sight penetrating a group of galaxies. The absorber
presumably traces multiple phases of cool ($T \sim 10^4$ K) photoionized
intragroup medium. The inferred C/O < 0 hints at preferential enrichment from
core-collapse supernovae, with such gas displaced from one or more of the
nearby galaxies, and confined to the group medium.
We present an analysis of the galaxy environment and physical properties of a partial Lyman limit system at z = 0.83718 with HI and metal line components closely separated in redshift space ...(\(|\Delta v| \approx 400\) km/s) towards the background quasar HE1003+0149. The HST/COS far-ultraviolet spectrum provides coverage of lines of oxygen ions from OI to OV. Comparison of observed spectral lines with synthetic profiles generated from Bayesian ionization modeling reveals the presence of two distinct gas phases in the absorbing medium. The low-ionization phase of the absorber has sub-solar metallicities (1/10-th solar) with indications of C/O < 0 in each of the components. The OIV and OV trace a more diffuse higher-ionization medium with predicted HI column densities that are \(\approx 2\) dex lower. The quasar field observed with VLT/MUSE reveals three dwarf galaxies with stellar masses of \(M^* \sim 10^{8} - 10^{9}\) M\(_\odot\), and with star formation rates of \(\approx 0.5 - 1\) M\(_\odot\) yr\(^{-1}\), at projected separations of \(\rho/R_{\mathrm{vir}} \approx 1.8 - 3.0\) from the absorber. Over a wider field with projected proper separation of \(\leq 5\) Mpc and radial velocity offset of \(|\Delta v| \leq 1000\) km/s from the absorber, 21 more galaxies are identified in the \(VLT\)/VIMOS and Magellan deep galaxy redshift surveys, with 8 of them within \(1\) Mpc and \(500\) km/s, consistent with the line of sight penetrating a group of galaxies. The absorber presumably traces multiple phases of cool (\(T \sim 10^4\) K) photoionized intragroup medium. The inferred C/O < 0 hints at preferential enrichment from core-collapse supernovae, with such gas displaced from one or more of the nearby galaxies, and confined to the group medium.
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