Fermi-LAT observations of the surprising SNR G150.3+4.5

J. Devin1, M.-H. Grondin1, J. W. Hewitt2, M. Lemoine-Goumard1 on behalf of the Fermi-LAT Collaboration

1 Centre d’Études Nucléaires de Bordeaux-Gradignan (CENBG) / CNRS-IN2P3 - France 2 University of North Florida, Jacksonville - USA

Conclusions

Morphological analysis

Spectral analysis

The SNR G150.3+4.5 is adequately described by a uniform disk from 1 GeV to 1 TeV. The hard GeV spectrum point towards a leptonic origin of the emission and an acceleration of particles at least up to TeV energies. We are currently investigating the low-energy part of the spectrum to better constrain the origin of the emission from G150.3+4.5 and from 4FGL J0426.5+5434 in order to discuss their possible association. In five hours, CTA will detect significantly G150.3+4.5 and will provide insights concerning the highest particle energy achieved in this likely young SNR.

A new radio shell in the sky

Abstract: G150.3+4.5 has been detected as a faint radio supernova remnant with an angular size of 3°, suggesting an old or a nearby SNR. Extended gamma-ray emission spatially coincident with the radio morphology has been reported in the Fermi-LAT Galactic Extended Sources catalog, revealing a hard spectral index from 10 GeV to 2 TeV. A dedicated Fermi-LAT data analysis from 5 GeV to 500 GeV confirmed the hard spectral shape, similar to that observed in young shell-type SNRs such as RX J1713.7–3946 or RCW 86. However, no non-thermal X-ray emission from G150.3+4.5 has been reported, challenging our understanding on the origin of the emission. Using 10 years of Fermi-LAT data, we investigate the morphology and the spectral properties of the SNR G150.3+4.5, from 1 GeV to 1 TeV, to constrain the origin of the emission. This newly discovered SNR may be one of the closest GeV gamma-ray SNRs and one of the best SNR candidates, as a bright TeV object, that could be observed with the next generation of Cherenkov telescopes (CTA, Cherenkov Telescope Array).

[1] Gerbrandt et al. 2014, A&A, 566 [2] Gao and Han, 2014, A&A, 567 [3] Mysore et al., 2015, poster at the Fermi Symposium [4] Ackermann et al., 2017, ApJ, 843 [5] 4FGL catalog, Fermi-LAT collaboration, 2019 [6] http://www3.mpifr-bonn.mpg.de/survey.html [7] https://www.cta-observatory.org

Contact: jdevin.phys@gmail.com

Previous gamma-ray studies

The brightest part of the shell (box A in Figure 1) was first detected by [1] with a radio spectral index of ……………….….… . [2] confirmed the non-thermal emission from the overall remnant. The large angular size of 3° suggests either an evolved or a nearby SNR.

No X-ray studies have been reported so far and no significant emission appears in ROSAT, Integral/IBIS and Swift/BAT archival data.

Figure 1. Urumqi (6 cm) data ([2]). The boxes A and B are the brightest parts of the shell (represented by a red dotted circle).

Using HI data, the more likely distance for G150.3+4.5 is d = 0.6 kpc ([3]), in agreement with its hard spectrum, similar to that obtained for young TeV SNRs. In this case, G150.3+4.5 would be one of the closest GeV gamma-ray SNRs.

Figure 2. Comparison of the spectrum of G150.3+4.5 with other spectra from old and young SNRs (taken from [3]), favoring the young SNR scenario for G150.3+4.5.

Analysis with:

more than 10 years of Fermi-LAT data the latest diffuse emission models and source catalog ([5]) all the events from 1 GeV to 1 TeV a region of interest (ROI) of 26° x 26° a model including sources up to 20° from the ROI center

Using the Fermipy package, we:

localize and test the extension of 4FGL J0426.5+5434 (lying in the South of the SNR) using a Gaussian model localize and find the extension of G150.3+4.5 (4FGL J0427.2+5533e) using a uniform disk model

Results:

The source 4FGL J0426.5+5434 is not extended

For G150.3+4.5:

Figure 3. Residual count map without G150.3+4.5 in the model (black: 4FGL sources, cyan: best-fit disk model). The full circle is the best-fit radius with the associated statistical errors (dashed circles). The green radio contours represent the brightest parts of the shell (from Urumqi 6 cm data, [6]).

Figure 4. Residual count maps from 1 GeV to 10 GeV and from 10 GeV to 1 TeV, without G150.3+4.5 and 4FGL J0426.5+5434 in the model. The best-fit disk from 1 GeV to 1 TeV is represented in cyan.

The source 4FGL J0426.5+5434 dominates the gamma-ray emission up to 10 GeV while the SNR becomes brighter at higher energies.

G150.3+4.5

4FGL J0426.5+5434

Eb = 8.97 GeV<latexit sha1_base64="8O3u7CDx3SMrPMw4lEuHZB+cUzQ=">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</latexit>

Figure 5. Spectral energy distribution of G150.3+4.5 from 1 GeV to 1 TeV with the associated statistical errors. The CTA North sensitivities (obtained with 0.5 and 5 hours for point sources) are also represented ([7]).

Logarithmic parabola (LogP): Power law (PL):

The spectrum is not significantly curved and point towards a leptonic origin of the emission. The GeV spectrum is harder than from previous gamma-ray studies and favors the young SNR scenario.

E0 = 0.65 GeV<latexit sha1_base64="d1tvjr3igU3UIzcqVyKQaoayP6c=">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</latexit>

References

↵ = �0.38± 0.10<latexit sha1_base64="GWxKEjKSm4a9CAKGgC3uQytuOf8=">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</latexit>

E0 = 8.97 GeV<latexit sha1_base64="wf9JHOVqZtp/PzhGhGY5kkMvyXs=">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</latexit>

Spectral index:

……………. ………. from 50 to 500 GeV [3] …………… from 10 GeV to 2 TeV [4]� = �1.88± 0.06

<latexit sha1_base64="PBMUD3zmKIXS8bkzxhNl2zkiRRQ=">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</latexit>

Power law:

TSext = 598.0<latexit sha1_base64="mkpgLwHokEO1O9fTJ8qQi8SOH8w=">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</latexit>

� = 1.76± 0.03<latexit sha1_base64="nDmf0JiE88NCBRPWpq3I0T4C1aQ=">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</latexit>

N0 = (6.53± 0.35)⇥ 10�14 cm�2s�1MeV�1<latexit sha1_base64="4r2c8hYyoPVpJ60hVU+Tx8RNeh4=">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</latexit>

N0 = (7.06± 0.44)⇥ 10�14 cm�2s�1MeV�1<latexit sha1_base64="uxE4AfjSK5NPsFTVoIFQg41sIfs=">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</latexit>

↵ = 1.69± 0.05<latexit sha1_base64="/5+ZMJ1xeLUHxwmvVx2VnCIpZnE=">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</latexit>

� = 0.04± 0.02<latexit sha1_base64="qPXE+u3OlDNVr7DHR6KB2mJt2UM=">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</latexit>

N0 = (2.48± 0.36)⇥ 10�11 cm�2s�1MeV�1<latexit sha1_base64="GhCdtsl9I+gkRbp8TQ0CnzWPVZM=">AAADI3icjVFNT9VAFD3UL8Svhy7dTHwxwYXN9EGUjQnRjRsMJL4HCQ9e2mGACZ22mZmSkKY/x3/ijh0xMS7Yg1v9AdyZVxKVGJ2m7bnnnnNn7tysypV1nH+biW7cvHX7zuzduXv3Hzx81Jt/PLJlbYQcijIvzWaWWpmrQg6dcrncrIxMdZbLjezwnc9vHEljVVl8dMeV3NbpfqH2lEgdUZPezodJw1v2hi0M4qVlNq404/Hiqxds7JSWliV8p3mZJC0bH9gqFbLh8UBoCo1uhKbcoG1ZiKwXttPMqhxNo0mvz2MeFrsOkg700a21svcVY+yihEANDYkCjnCOFJaeLSTgqIjbRkOcIaRCXqLFHHlrUklSpMQe0nefoq2OLSj2NW1wC9olp9eQk+E5eUrSGcJ+Nxbydajs2b/VbkJNf7Zj+mddLU2swwGx//JdKf/X53tx2MNy6EFRT1VgfHeiq1KHW/EnZ7905ahCRZzHu5Q3hEVwXt0zCx4bevd3m4b8eVB61sei09a48KekASd/jvM6GA3iZDFO1pf6K2+7Uc/iKZ5hgeb5Git4jzUMqfZnfMcP/Iw+RSfRafRlKo1mOs8T/Lais0tQW7FX</latexit>

� = 3.54± 0.15<latexit sha1_base64="TsMPpzM/og9zdA0kXD/lQgZoF/A=">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</latexit>

Best-fit power law Best-fit logarithmic parabola

PRELIMINARY

CTA North 0.5 h

CTA North 5 h

G150.3+4.5

�TSPL!LogP = 4.8<latexit sha1_base64="7Gelrh5bq051L8B24M6UD1MYVh4=">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</latexit>

� = �1.91± 0.09<latexit sha1_base64="WjU2YDgg8pc5qwQLvL5vF4GniTQ=">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</latexit>

PRELIMINARY PRELIMINARY

r = 1.593� ± 0.022�<latexit sha1_base64="uQGk3DxaOMsmQzuaoP/5hlBzDtM=">AAAC6HicjVHLLgRBFD3T3uM1WNpUTCRWk+5BsJBM2FiSGCQG6S6Fol+prpbIZD7Azk5s/YAtXyL+gL9wq/QkHhGq0933nnvOqbp1gzSUmXbdl5LT09vXPzA4VB4eGR0br0xM7mRJrrho8iRM1F7gZyKUsWhqqUOxlyrhR0EodoOLdVPfvRQqk0m8ra9ScRD5p7E8kdzXBB1VqoqtMq+2uDJ/2G5xqXiHtdKIuTW3Xu8ixKLcLvYz8IqgimJtJpVntHCMBBw5IgjE0BSH8JHRsw8PLlLCDtAmTFEkbV2ggzJpc2IJYviEXtD3lLL9Ao0pN56ZVXPaJaRXkZJhljQJ8RTFZjdm67l1Nuhv3m3rac52Rf+g8IoI1Tgj9C9dl/lfnelF4wTLtgdJPaUWMd3xwiW3t2JOzj51pckhJczEx1RXFHOr7N4zs5rM9m7u1rf1V8s0qMl5wc3xZk5JA/a+j/NnsFOvefM1b2uh2lgrRj2Iacxgjua5hAY2sIkmeV/jAY94cs6dG+fWufugOqVCM4Uvy7l/B7opm40=</latexit>

PRELIMINARY

In the catalog, the source 4FGL J0426.5+5434 has a pulsar-like spectrum (described by a logarithmic parabola with a break energy at 650 MeV). Since the curvature is not seen above 1 GeV, we describe the emission by a power law.

JD, MHG and MLG acknowledge support from Agence Nationale de la Recherche (grant ANR- 17-CE31-0014).