English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

3C454.3 is a widely studied and monitored flat spectrum radio quasar. We use the observations from the Small and Moderate Aperture Research Telescope System (SMARTS) to analyze the long-term optical and spectral variabilities of 3C454.3 at B, V, R, J, and K (BVRJK) bands. Based on the relation: F] ∝ ], we calculate the multiband spectral indices (α) and analyze the relations between α and F], where F] is the flux density at ] band (]=B, V, R, J, K). Main results are as follows. (1) The largest variations at BVRJK bands are ΔB = 3.37±0.08 mag, with the timescale ΔTB ≈ 1015 days, at B band; ΔV = 3.31±0.07 mag, with the timescale ΔTV ≈ 1014 days, at V band; ΔR = 3.62±0.12 mag, with the timescale ΔTR ≈ 679 days, at R band; ΔJ = 4.08±0.01 mag, with the timescaleΔTJ ≈ 763 days, at J band; andΔK = 5.03±0.03mag, with the timescaleΔTK ≈ 2715 days, at K band. (2)We analyze the long-term BVRJK lightcurves and obtain the quasiperiodicities: P1 = 86.92 ± 2.21 days, P2 = 204 ± 8.1 days, and P3 = 1.24 ± 0.19 years. (3) Multiband lightcurves show time delays: τVB = 0.15 ± 0.12 days, τRB = 0.37 ± 0.28 days, τJB = 0.58 ± 0.40 days, and τKB = 1.02 ± 0.47 days. (4) The relations between α and F] show strong correlations, which are typical RWB behaviors; when the source turns to be brighter, the spectral indices turn to be redder.

Long-Term Optical and Spectral Variability of FSRQ 3C454.3