EROSITAwiki: ECProposalMarkowitz

EroCompact EC Proposal 49

Proposal Date :

• Changed : 11-Apr-2022 by Mara Salvato : confirmation

Summary of activities by EC Alex Markowitz on follow-ups of eROSITA-detected Changing-look/flaring AGN candidates during 2024:

1) Markowitz is the PI of continuing SALT proposals, and/or access to Polish GT time at SALT, to obtain spectroscopic monitoring for selected eROSITA-detected CLAGN. In 2024 alone, we triggered SALT observations for six different CLAGN for extended-baseline monitoring.

2) Paper proposal accepted for CLAGN shutdown event eRASSt_J124028.45-230931.97, with Markowitz as first author: "A Changing-Look Seyfert discovered by eROSITA reveals a temporary accretion-rate dip and BLR “breathing." Markowitz has done X-ray spectral modeling, broadband SED fits, optical spectral fits, optical photometric reduction, and has assembled an outline for the manuscript.

3) Publications in 2024:

(see point 2) Paper by A. Markowitz, M. Krumpe, D. Homan, et al., "eROSITA detection of a cloud obscuration event in the Seyfert AGN EC 04570-5206" published, 2024, A&A, 684, A101. Markowitz led analysis and publication on the three-year multi-wavelength campaign on this CLAGN.

Paper led by S. Krishnan (former CAMK PhD student), "An X-ray flaring event and a variable soft X-ray excess in the Seyfert LCRS B040659.9–385922 as detected with eROSITA" accepted and published, 2024, A&A, 691, A102.

4) Continued work on manuscript led by T.\ Saha (former PhD student at CAMK) on CLAGN event eRASSt_J042838.58-000041.81, submitted to A&A: "Multiwavelength study of extreme variability in LEDA 1154204: A changing-look event in a type 1.9 Seyfert." The paper is still under review; the refereeing process is taking much longer than expected. Markowitz has been involved in re-analysis and text rewrites during 2024. In addition, Saha defended his thesis (which used eROSITA data and included simulations based on eROSITA responses) in Spring 2024.

5) Disseminated eROSITA-based results via a) a talk at various workshops

6) Consulting with M. Krumpe on triggering X-ray ToOs.

7) Hosted a visit to CAMK-Warsaw by Dusan Tubin, PhD student at AIP-Leibniz, for discussions and guidance on AGN variability simulations for Dusan's work on using eRASS data to search for periodic signals and supermassive black hole binary systems.

PLANS/GOALS FOR 2025: We request an extension on the EC to enable Markowitz to continue analysis and publication on individual eRASS-detected CLAGN candidates for which we have collected extensive multi-wavelength data. Tasks include finishing and submitting the manuscript on eRASSt_J124028.45-230931.97 (optimistically by Spring/Summer 2024), continuing to collect additional spectroscopic monitoring of selected targets at SALT, and starting analysis on new objects (e.g., ignition candidate event eRASSt_J000009.24-772027.95)

Summary of activities by EC Alex Markowitz on follow-ups on eROSITA-detected extragalactic transients during 2023:

1) Markowitz is the PI of continuing SALT proposals, and/or access to Polish GT time at SALT, to obtain spectroscopic monitoring for eROSITA-detected transient AGN. We have triggered SALT observations on fifteen different CLAGN since December 2020, with six SALT observations in 2023 alone, most focused on extended-baseline monitoring.

2) Markowitz has been the PI of a continuing program at Las Cumbres Observatory to obtain optical photometric monitoring for selected targets (18 hours total across three semesters; telescope time was purchased through July 2023). Since February 2022, we triggered a total of 46 observations on 20 CLAGN targets (18 observations during 2023 alone).

3) Markowitz has assisted with writing multiple X-ray observing proposals for Swift, NuSTAR, NICER, and XMM-Newton, as well as in XMM-Newton DDT requests, submitted by M. Krumpe. Markowitz is also a co-investigator on ESO proposals submitted by D. Homan and M. Krumpe.

4) Markowitz led analysis and publication on the X-ray shutdown event J0458-52. He led X-ray spectral modeling, SED fits, and optical spectral fits on data taken during the three-year observing campaign. The manuscript was submitted to A&A in August 2023, and accepted in December 2023. He has also recently started the multiwavelength analysis of another CLAGN, J1240-2309.

5) PhD student Krishnan has been leading analysis and manuscript writing for the CLAGN transient J0408-38. She conducted X-ray spectral fits, broadband SED modeling, and optical spectral analysis. Krishnan has been writing the manuscript, which was submitted to A&A in December 2023. In Spring 2023, she also completed and defended her PhD dissertation, one chapter of which encompassed this eROSITA work.

6) In addition, Markowitz, Saha, and Krishnan were co-authors on D. Homan et al. (2023, A&A, 672, A167). Markowitz was a co-author on Z. Liu et al. (2023, A&A, 669, A75)

Summary of activities by EC A. Markowitz, PhD student Saikruba Krishnan (saikruba@camk.edu.pl), and PhD student Tathagata Saha (tathagata@camk.edu.pl) on follow-ups on eROSITA-detected Changing-look/flaring AGN during 2022:

1) Markowitz is the PI of continuing SALT proposals, and/or access to Polish GT time at SALT, to obtain spectroscopic monitoring for eROSITA-detected CLAGN. He has triggered SALT monitoring observations on fourteen CLAGN since December 2020 (with 19 SALT observations in 2022 alone).

2) Markowitz is the PI of a continuing program at Las Cumbres Observatory to obtain optical photometric monitoring for selected targets (18 hours total across three semesters). Since February 2022, he has triggered 28 observations on 12 CLAGN targets. Telescope time is purchased through July 2023.

3) Markowitz and Saha have assisted with writing multiple X-ray observing proposals for Swift, NuSTAR, NICER, and XMM-Newton, as well as in XMM-Newton DDT requests, submitted by M. Krumpe. They have also been consulting with M. Krumpe on triggering X-ray ToOs. Markowitz is also a co-investigator on ESO proposals submitted by D. Homan and M. Krumpe. Saha has also just submitted a Chandra DDT request.

4) Markowitz has been leading analysis on shutdown event CLAGN J0458-52, with new X-ray data continuing through early 2022. He has conducted X-ray spectral modeling, SED fits, and optical spectral fits. He is currently assembling the manuscript for publication, with an estimated submission date in February 2023. He is also supervising the two PhD students, Krishnan & Saha.

5) PhD student Krishnan has been leading analysis and manuscript writing for the CLAGN transient J0408-38, with new monitoring data being procured into 2022. She has been conducting X-ray spectral fits, broadband SED modeling, optical spectral analysis. She has been writing the manuscript, with submission expected by December 2022 or January 2023. She also also been writing her PhD thesis, one chapter of which will encompass her eROSITA work, with defense expected by Spring 2023.

6) PhD student Saha has been leading analysis of the transient flaring CLAGN J0428-00. He has been fitting the optical spectra, and modeling of optical and IR light curves to trace behavior of the disk and circumnuclear dust, respectively. He has been writing the manuscript, with expected submission in early 2023.

Co-authorship: Two papers led by D. Homan and Z. Liu, submitted in 2022. Presentations: oral and poster presentations at several conferences/workshops in 2022

Update on Scientific Proposal

Summary of A. Markowitz's activities on follow-ups on ROSITA-detected Changing-look AGN:

1) Alex is the PI on two consecutive multi-semester SALT proposals to obtain the first dedicated spectroscopic monitoring for eROSITA-detected CLAGN, with observations since December 2020, and ongoing through October 2022; triggering SALT monitoring observations on seven CLAGN so far.

2) Currently he is using his funds to buy time on the Las Cumbres Observatory global network to obtain long-term optical light curves of several AGN ignition and shut-down events.

3) He helped with writing and proof-reading multiple X-ray observing proposals for Swift, NuSTAR, & XMM-Newton, as well as in XMM-Newton DDT requests, submitted by M. Krumpe. He has been involved in the discussions regarding which events should require additional X-ray and optical follow-ups. He is also a co-investigator on ESO proposals submitted by D. Homan and M. Krumpe.

4) He is leading the publication on the AGN shutdown event CLAGN J0458-52, as this object is one of his first SALT spectral monitoring triggers. The X-ray data reduction and fitting is completed. Currently a paper draft is generated and will be presented to eROAGN soon. We are also incorporate results from newest X-ray data, optical photometry, and optical spectroscopy in this publication.

5) Alex assisted in the X-ray analysis for more ignition and shut-down events (e.g., ignition event J2344-35).

6) He is supervising CAMK PhD students T. Saha and S. Krishnan on various tasks, including fitting X-ray spectral data for several objects (SK & TS), fitting optical continuum light curves (TS) simulations on using hardness ratios to track occultation events in the NRTA (TS).

List of Potential Collaborators within eROSITA_DE

eroTDA, eroAGN members

Expected Outcome

Scientific paper; catalogue of counterparts.

Expected duration of the project

yearly renewal based on review