Computations in Radio-Frequency Spectroscopy

Ball, John A.

doi:10.1016/b978-0-12-460814-6.50009-7

Cited by 3 publications

(2 citation statements)

References 13 publications

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“…We find nine such objects, which we fit with PSFs/Gaussians to get their positions in each of the images, separately. These are always found to be in agreement for each source within their respective intrinsic positional uncertainty in the VLA image, which can be estimated as 1 2 FWHM (S/N) (Ball 1975;Condon 1997). We also repeat the same exercise with respect to the ALMA 870 𝜇m image and draw the same conclusion, although with only 4 sources that are detected at 6𝜎 at 3 GHz.…”

Section: Origin Of the Radio Emissionssupporting

confidence: 68%

Feedback Factory: Multiple faint radio-jets detected in a cluster at z=2

Kalita,

Daddi,

Coogan

et al. 2021

Preprint

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We report the detection of multiple faint radio sources, that we identify as AGN-jets, within CLJ1449+0856 at z=2 using 3 GHz VLA observations. We study the effects of radio-jet based kinetic feedback at high redshifts, which has been found to be crucial in low redshift clusters to explain the observed thermodynamic properties of their ICM. We investigate this interaction at an epoch featuring high levels of AGN activity and a transitional phase of ICM in regards to the likelihood of residual cold-gas accretion. We measure a total flux of 30.6 ± 3.3 𝜇Jy from the 6 detected jets. Their power contribution is estimated to be 1.2 (±0.6) × 10 44 ergs s −1 , although this value could be up to 4.7 × 10 44 ergs s −1 . This is a factor ∼ 0.25 -1.0 of the previously estimated instantaneous energy injection into the ICM of CLJ1449+0856 from AGN outflows and star formation, that have already been found to be sufficient in globally offsetting the cooling flows in the cluster core. In line with the already detected abundance of star formation, this mode of feedback being distributed over multiple sites, contrary to a single central source observed at low redshifts, points to accretion of gas into the cluster centre. This also suggests a 'steady state' of the cluster featuring non cool-core like behaviour. Finally, we also examine the TIR-radio luminosity ratio for the known sample of galaxies within the cluster core and find that dense environments do not have any serious consequence on the compliance of galaxies to the IR-radio correlation.

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Section: Origin Of the Radio Emissionssupporting

confidence: 68%

Feedback Factory: Multiple faint radio-jets detected in a cluster at z=2

Kalita,

Daddi,

Coogan

et al. 2021

Preprint

View full text Add to dashboard Cite

show abstract

“…We find nine such objects, which we fit with PSFs/Gaussians to get their positions in each of the images, separately. These are always found to be in agreement for each source within their respective intrinsic positional uncertainty in the VLA image, which can be estimated as 1/2 FWHM/(S/N) (Ball 1975;Condon 1997). We also repeat the same exercise with respect to the ALMA 870 μm image and draw the same conclusion, although with only four sources that are detected at 6σ at 3 GHz.…”

Section: Origin Of the Radio Emissionssupporting

confidence: 67%

Feedback factory: multiple faint radio jets detected in a cluster at z = 2

Kalita

Daddi

Coogan

et al. 2021

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

We report the detection of multiple faint radio sources, that we identify as AGN-jets, within CLJ1449+0856 at z=2 using 3 GHz VLA observations. We study the effects of radio-jet based kinetic feedback at high redshifts, which has been found to be crucial in low redshift clusters to explain the observed thermodynamic properties of their ICM. We investigate this interaction at an epoch featuring high levels of AGN activity and a transitional phase of ICM in regards to the likelihood of residual cold-gas accretion. We measure a total flux of $\rm 30.6 \pm 3.3~\mu Jy$ from the 6 detected jets. Their power contribution is estimated to be $1.2 ~(\pm 0.6)~ \times 10^{44} ~\rm ergs~ s^{-1}$, although this value could be up to $4.7 ~ \times 10^{44} ~\rm ergs~ s^{-1}$. This is a factor ∼0.25 – 1.0 of the previously estimated instantaneous energy injection into the ICM of CLJ1449+0856 from AGN outflows and star formation, that have already been found to be sufficient in globally offsetting the cooling flows in the cluster core. In line with the already detected abundance of star formation, this mode of feedback being distributed over multiple sites, contrary to a single central source observed at low redshifts, points to accretion of gas into the cluster centre. This also suggests a ‘steady state’ of the cluster featuring non cool-core like behaviour. Finally, we also examine the TIR-radio luminosity ratio for the known sample of galaxies within the cluster core and find that dense environments do not have any serious consequence on the compliance of galaxies to the IR-radio correlation.

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