论文标题
S4 0444+63中的扁平光谱耀斑通过新的多波长单次观测来揭示
A flat-spectrum flare in S4 0444+63 revealed by a new implementation of multi-wavelength single-dish observations
论文作者
论文摘要
相对论扩增增强了喷气基底对大麻总发射的贡献，从而使单盘观测值有用且可实现其物理状态，尤其是在增强的多波长活性的发作期间。在2017年7月Fermi-Lat检测到新的Gamma-ray源后，我们观察到S4 0444+63，以确保其作为伽马射线大黄花的识别。我们在2017年8月1日至2018年9月22日之间，在5、8和24 GHz的Medicina和Noto射程望远镜进行了观察，总共12个时期。我们通过现场交叉扫描进行了观察，并通过我们新开发的跨扫描分析渠道减少了数据，我们在此详细介绍了第一次详细介绍。我们发现，与历史值相比，无线电波长处的发射状态处于升高状态，而历史值持续了几个月。 2018年5月16日在24 GHz时达到了最大发光度，$ l_ {24} =（1.7 \ pm0.3）\ times10^{27} \ \ \ \ \ \ \ m rmm {w \，hz}^{ - 1} $;发现光谱指数从略微上升到略微陡峭。除了新的观察结果（事实证明是保护源识别）的有效和有效的工具外，其他单盘和非常长的基线干涉测量学数据还提供了对来源物理学的进一步见解。我们估计一个同步峰频率$ν_\ MATHRM {peak} = 10^{12.97} $ Hz，而多普勒因子超过$δ\ sim5.0 $，两种量都在来自源的伽马射线排放中起作用。
Relativistic amplification boosts the contribution of the jet base to the total emission in blazars, thus making single dish observations useful and practical to characterise their physical state, particularly during episodes of enhanced multi-wavelength activity. Following the detection of a new gamma-ray source by Fermi-LAT in July 2017, we observed S4 0444+63 in order to secure its identification as a gamma-ray blazar. We conducted observations with the Medicina and Noto radio telescopes at 5, 8, and 24 GHz for a total of 12 epochs between 2017 August 1 and 2018 September 22. We carried out the observations with on-the-fly cross scans and reduced the data with our newly developed Cross-scan Analysis Pipeline, which we present here in detail for the first time. We found the source to be in an elevated state of emission at radio wavelength, compared to historical values, which lasted for several months. The maximum luminosity was reached on 2018 May 16 at 24 GHz, with $L_{24}=(1.7\pm0.3)\times10^{27}\ \mathrm{W\,Hz}^{-1}$; the spectral index was found to evolve from slightly rising to slightly steep. Besides the new observations, which have proved to be an effective and efficient tool to secure the identification of the source, additional single dish and very-long-baseline interferometry data provide further insight on the physics of the source. We estimate a synchrotron peak frequency $ν_\mathrm{peak}=10^{12.97}$ Hz and a Doppler factor in excess of $δ\sim5.0$, with both quantities playing a role in the gamma-ray emission from the source.
