We report results from an 18-day ROSAT HRI monitoring campaign on the ultrasoft Narrow-Line Seyfert 1 (NLS1) class quasar PHL 1092. This luminous, radio-quiet quasar showed strong X-ray variability in a short ROSAT PSPC observation, and ROSAT HRI monitoring of the similar object IRAS 13224–3809 revealed extreme variability on intermediate timescales. We wanted to determine whether remarkable X-...

Background & Aim: In the present research, we investigated phytochemical characteristics of two important species of Verbascum genus. Enormous reconnaissance and field surveys were conducted to identify the most important natural habitats of Verbascum species in Kohgiluyeh va Buyerahmad province, southern Iran. Experimental: The aerial parts of Verbascum songaricum a...

Appears in: INTED2023 Proceedings Publication year: 2023Pages: 1092-1098ISBN: 978-84-09-49026-4ISSN: 2340-1079doi: 10.21125/inted.2023.0323Conference name: 17th International Technology, Education and Development ConferenceDates: 6-8 March, 2023Location: Valencia, Spain

We report a dramatic variability event in the X–ray history of the Narrow–Line quasar PHL 1092 (z = 0.396). Our latest 2008 XMM–Newton observation reveals a flux drop of ∼ 200 with respect to the previous observation performed about 4.5 years earlier, and a drop of ∼ 135 with respect to its historical flux. Despite the huge X–ray variation, the UV flux remains constant producing a very signific...